DAIMLER AG (formerly known as MERCEDES-BENZ AG) v. HELGE HERBERT LEIDUCK appointed by Order to represent the estate of HERBERT HEINZ HORST LEIDUCK, deceased AND ANOTHER

HCA 4089/1994

IN THE HIGH COURT OF THE

HONG KONG SPECIAL ADMINISTRATIVE REGION

COURT OF FIRST INSTANCE

ACTION NO 4089 of 1994

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J U D G M E N T

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The Competency Issue

1.  Before the court is what has become known in these proceedings as the “competency issue” which encompasses the following questions:

(1)  whether the late Mr Herbert Leiduck (“Mr Leiduck”) (who was until his death on 23 March 2014 the 1^st defendant in this action and one of the witnesses for the defendants) was, at the time of his examination on 30 January and 9 February 2014 by Professor Dr med Hans Förstl (“Dr Förstl”),[1] incompetent to give evidence in these proceedings within the meaning of section 3(b) of the Evidence Ordinance (Cap 8) (“EO”);

(2)  if so, since which date had Mr Leiduck become so incompetent;

(3)  in particular, whether Mr Leiduck was so incompetent on the dates when he swore/signed his affidavits/witness statements/answers to interrogatories, signed statements of truth verifying the defendants’ pleadings and gave oral evidence; and

(4)  whether and, if so, how likely Mr Leiduck might recover from his incompetence in the future.

2.  The answers to questions (1)[2] and (4)[3] have since lost significance as Mr Leiduck never resumed giving evidence after 22 August 2013 (save that his condition in January and February 2014 as observed by Dr Förstl might throw light in the retrospective assessment of his mental health in the preceding years).

3.  With regard to question (3), Mr Leiduck signed statements of truth to verify the defendants’ pleadings; answered interrogatories administered by the plaintiff on oath; swore/signed affidavits/witness statements and gave viva voce testimony from a business centre in Germany (where he resided) via video link as follows:[4]

Date	Event
7.1.2008	1st affidavit
9.12.2008	2nd affidavit
25.6.2009	3rd affidavit
30.3.2010	4th affidavit
6.4.2010	(1st) 5th affidavit (which sought to confirm all matters in the defendants’ pleadings that had not been expressly verified or otherwise mentioned or dealt with in any of Mr Leiduck’s affidavits)
16.11.2010	Statement of truth of smended points of claim re fraud
27.9.2011	(2nd) 5th affidavit
11.1.2012	6th affidavit
19.9.2012	Witness statement
15.11.2012	Supplemental witness statement
15.12.2012	Statement of truth of consolidated points of claim
23.1.2013	Statement of truth of consolidated points of reply
28.1.2013	Answer to interrogatories
25.2.2013	Examination in chief and cross‑examination
27.2.2013	Cross‑examination
1.3.2013	Cross‑examination
5.3.2013	Cross‑examination
6.3.2013	Cross‑examination
7.3.2013	Cross‑examination
10.4.2013	Cross‑examination
11.4.2013	Cross‑examination
8.5.2013	Cross‑examination
9.5.2013	Cross‑examination
13.5.2013	Cross‑examination
14.5.2013	Cross‑examination
15.5.2013	Cross‑examination
6.6.2013	Cross‑examination
7.6.2013	Cross‑examination
16.8.2013	Cross‑examination & re‑examination
19.8.2013	Re‑examination
21.8.2013	Re‑examination
22.8.2013	Re‑examination

4.  Section 3(b) of the EO provides as follows:

“The following persons only shall be incompetent to give evidence in any proceedings‑

(a) (Repealed 70 of 1995 s 2)

(b) persons of unsound mind, who, at the time of their examination, appear incapable of receiving just impressions of the facts respecting which they are examined or of relating them truly; and no person who is known to be of unsound mind shall be liable to be summoned as a witness without the consent previously obtained of the court or person before whom his attendance is required.” (emphasis added)

5.  The competency issue, including the terms of question (3) and the written evidence to be included in that question (see para 3 above), was drafted by agreement between the parties and approved by me by para 1 of the Order dated 5 November 2013 as amended on 24 December 2014.

6.  Although the relevant dates in question (3) were identified by agreement between the parties after the hearing on 5 November 2013 and it was the plaintiff who specifically asked for the dates when Mr Leiduck signed the statements of truth relating to the defendants’ pleadings to be included in question (3),[5] Mr John Yan SC (leading Ms Sara Tong) pointed out in their closing submissions on the competency issue that EO section 3(b) prevents persons who are incompetent within its meaning from giving evidence and a person is not giving evidence by signing a statement of truth in respect of a pleading or an answer to interrogatory.

7.  On reflection, I tend to agree that one is not, in ordinary parlance, giving evidence in signing a statement of truth verifying a pleading so that section 3(b) has no application to such an act.

(1)  The primary purpose of the requirement for a pleading to be verified by a statement of truth is to ensure that such document accurately reflects the true case of the party who puts forward it and to discourage pleadings which are unsupported by evidence, are either untrue or wholly speculative and which are put forward in the hope that something will turn up during discovery or the trial.  See Hong Kong Civil Procedure 2017, vol 1, para 41A/1/1.

(2)  In this regard, I note from the provisions in Order 41A, rule 3(1)(b), (2), (3), (4), (6), (7), (8), (9) and (10) of the Rules of the High Court (Cap 4A) that a statement of truth in respect of a pleading is required to be signed by a responsible person of the party who puts it forward, as opposed to a person or persons whose evidence will prove the facts asserted in the pleading.

(3)  A pleading, even verified by a statement of truth, does not function, and cannot be adduced, as evidence.  The facts asserted in a pleading so verified will still have to be proved in the usual way by evidence in the proper sense of the word.

8.  As Mr Leiduck was not giving evidence when he signed the statements of truth respecting the defendants’ pleadings, there is no need to investigate his competence as a witness when he signed those statements of truth on 16 November 2010, 15 December 2012 and 23 January 2013.

9.  Answers to interrogatories, however, stand on a different footing, to which section 3(b) applies.

(1)  The administration of interrogatories is part of the process of discovery of facts.  See Hong Kong Civil Procedure 2017, vol 1, para 26/0/2. 

(2)  Answers to interrogatories are given on oath. 

(3)  Answers to interrogatories, when put in, form part of the general body of the evidence in the case.  See Hong Kong Civil Procedure 2017, vol 1, para 26/7/1.

(4)  In this instance, the only remaining relevant answer[6] in Mr Leiduck’s Answers to Interrogatories dated 28 January 2018 arose out of and is related to what Mr Leiduck had said in para 13 of his witness statement dated 19 September 2012.

I shall therefore have to inquire into Mr Leiduck’s competency when he signed the Answers to Interrogatories on 28 January 2013.

These Proceedings

10.  This action was commenced on 30 April 1994 by the plaintiff (then known as Mercedes Benz AG) to recover certain monies[7] (together with interest) that had been advanced by it to one Intercontinental Resources Societé Anonym Monegasque (“IRSAM”), a company incorporated in the Principality of Monaco and of which Mr Leiduck was the sole owner and president, pursuant to an agreement contained in or evidenced by a letter dated 8 July 1993 from the plaintiff to IRSAM.

11.  Prior to the issue of the writ of summons herein on 30 April 1994, on 29 April 1994, the plaintiff applied for and obtained a mMareva injunction (“injunction”) against both Mr Leiduck and Intercontinental Resources Company Limited (“IRC”), a company incorporated in Hong Kong and of which Mr Leiduck was a 99.998% shareholder and a director, upon the usual cross‑undertaking as to damages (“undertaking”).

12.  The injunction was applied for and granted on the strength of an affidavit made on 29 April 1994 by Mr Paul John Carolan, then a partner of Baker & McKenzie (“B&M”), former solicitors for the plaintiff.  More particularly, the plaintiff joined IRC as the 2^nd defendant and sought to attach IRC with liability as a constructive trustee on the basis that it had received information from one Jacques Lefort (“Lefort”), a magistrate in Monaco investigating various criminal complaints against Mr Leiduck, that US$6 million of the monies paid by the plaintiff to IRSAM had been misapplied towards the repayment of a loan of which IRC was a co‑borrower in July 1993. 

13.  In fact, this information was wrong.  The monies advanced by the plaintiff to IRSAM had not been used by or for the benefit of IRC.

14.  By a letter dated 14 May 1994 from B&M to IRC’s then solicitors, the plaintiff advised IRC that it would have the injunction discharged as against IRC and would not resist an order for costs in favour of IRC provided that IRC would not claim damages pursuant to the undertaking.  The parties’ solicitors then agreed over the telephone and confirmed by letters on 16 May 1994 that the plaintiff would pay IRC’s costs and disbursements on an indemnity basis and that IRC would make no claim for damages pursuant to the undertaking (“settlement agreement”).

15.  The injunction was discharged by consent, and the action discontinued, as against IRC on 17 May and 22 August 1994 respectively.

16.  As against Mr Leiduck, the service of the writ of summons herein on him in Monaco was, after the plaintiff’s unsuccessful appeals to the Court of Appeal and Privy Council, finally set aside and the injunction against Mr Leiduck discharged on 26 July 1995 for want of jurisdiction over him by the Hong Kong courts.

Defendants’ Application and Case for an Inquiry as to Damages Caused to them by the Injunction

17.  Then, after the lapse of more than 10 years, by a summons issued on 23 July 2007, in enforcement of the undertaking, the defendants apply for an inquiry as to the damages suffered by them by reason of the injunction and for payment of the sum(s) found due upon such inquiry.

18.  It is unnecessary for present purposes for me to set out the defendants’ entire case for an inquiry as to damages.  I shall identify only those aspects to which Mr Leiduck’s evidence may relate.

19.  First, on liability, having agreed not to enforce the undertaking, it is incumbent upon IRC to have the settlement agreement set aside before it can claim damages. In this regard, IRC’s case for setting aside the settlement agreement is premised partly[8] upon:

(1)  the plaintiff having bribed Lefort for information that he had obtained from his investigation into the affairs of Mr Leiduck and companies controlled by him including IRC as follows:

(a) that in about early 1994, Lefort indicated to one Dieter Fink (“Fink”), a former sale executive in charge of the plaintiff’s Eastern European Operations, that he wanted to obtain a “classy” Mercedes car at “a cheap price”, which indication was meant and understood to be a request for a luxurious Mercedes Benz car as a free gift in return for co‑operating with the plaintiff;

(b) that Fink passed on such request to a director of the plaintiff in charge of sales surnamed Hubbert (“Hubbert”); and

(c)  that in about February 1994, Lefort received money in cash from an employee of the plaintiff and purchased a Mercedes Benz E300 from distributeur SAMGF in exchange for Lefort providing to the plaintiff information that he obtained from his investigation into the affairs of Mr Leiduck and companies controlled by him including IRC; and 

(2)  the defendants first discovering that the plaintiff had obtained information from Lefort through bribery on 16 March 2006 when Mr Leiduck had a telephone conversation with Fink who told him about Lefort’s said request and his passing the same onto Hubbert.

20.  As for damages, the defendants claim damages under 2 heads.  Firstly, Mr Leiduck or alternatively IRC claim to have suffered loss of profits (in the form of commissions to the tune of €90 million minus expenses) under a housing development project to build 15,000 houses in the Leningrad and Tula regions of Russia for the Russian Armed Forces withdrawing from East Germany following the dissolution of the Warsaw Pact (“housing project”). 

21.  Secondly, it is also the defendants’ case that the injunction ruined IRC.  IRC claims damages for loss of the value of its business.  Alternatively, Mr Leiduck, holding 99,998 out of the 100,000 shares of and in IRC, claims to have lost the opportunity to sell his IRC shares.

Mr Leiduck’s Evidence

22.  To put the discussion and assessment of Mr Leiduck’s competence as a witness in context, it is useful to have an outline of his evidence.

23.  In this regard, for reasons that will become apparent shortly (see para 94‑96 below), it is not necessary for me to be concerned with Mr Leiduck’s testimony in court.

24.  Turning then to his written evidence, I note at the outset that much of Mr Leiduck’s affidavits, witness statements and answers to interrogatories (though voluminous) in fact dealt with many matters that are strictly speaking irrelevant (or have since become irrelevant) to the defendants’ claim for damages against the plaintiff pursuant to the undertaking (and which I shall for such reason have to ignore in deciding whether the defendants are entitled to an inquiry of damages).  Obvious examples include Mr Leiduck’s version of the transaction giving rise to the plaintiff’s substantive claims against him in this action and how and why it did not go through; what Mr Leiduck saw as the plaintiff’s persecution of him, including the pursuit of criminal complaints and prosecution against him in Monaco; the treatment received by Mr Leiduck under the criminal justice system in Monaco particularly his incarceration in a Monegasque prison for 33 months from 19 October 1993 to 22 June 1996 without trial, followed by convictions of charges which Mr Leiduck said were trumped up before the criminal court in Monaco on 23 May 2000 and a sentence of a term of imprisonment which Mr Leiduck did not actually serve; what an independent French parliamentary report by a taskforce of the National Assembly of France said about the handling of Mr Leiduck’s case by Monaco; the various efforts made by Mr Leiduck after May 2000 to clear his name; Mr Leiduck’s rebuttal of the plaintiff’s allegations that he had defrauded various third parties; the alleged inducement and intimidation by the plaintiff of Mr Philip Yip (“Yip”), the then general manager of IRC, to agree on behalf of IRC not to claim damages by a promise of business dealings with Yip and a threat to sue Yip personally (which allegations, though made on affidavit, do not form part of the defendants’ pleaded case); and the investigation and evidence of two investigators that the defendants no longer rely on as indicated by Mr Horace Wong SC (leading Mr Clark Wang) on Day 4 (7 February 2013).

25.  Further, in view of the statutory test of incompetence (see para 4 above), we may also put aside matters that were clearly spoken to by Mr Leiduck not from his personal perception and recollection, eg where he was merely repeating the contents of a document[9] and where he was expressly reiterating what he had been given to understand by others.[10]

26.  In short, I shall concentrate on matters that Mr Leiduck necessarily deposed to first hand from his personal perception and recollection.

27.  In this regard, first, in support of the defendants’ case for the setting aside of the settlement agreement, Mr Leiduck’s 1^st affidavit (para 8, 15, 16 and 17) and 2^nd affidavit (para 2, 4, 5 and 6) dealt with the alleged bribery of Lefort by the plaintiff by setting out Mr Leiduck’s telephone conversation with Fink on 16 March 2006; a subsequent telephone call made by Mr Leiduck to one Dieter Schultz (a director of the plaintiff in charge of finance) who told Mr Leiduck that the car would not be supplied from Stuttgart but made available through a local dealer (which conversation Mr Leiduck relied on as corroborating what Fink had told him); and a letter dated 27 March 2006 written by Mr Leiduck to Mr Karl Ulmer, his lawyer in Germany, advising him of his telephone conversation with Fink on 16 March 2006.

28.  Second, in support of the defendants’ claim for damages for loss of commissions under the housing project, Mr Leiduck deposed to his “good relations with the Russians”; the signing of, inter alia, a memorandum of understanding dated 23 December 1991 between the Russian Ministry of Defence, Russia’s State Military Industrial Association Konversija, the Urban Development GMBH and IRSAM (represented by Mr Leiduck); IRC’s initial intended technical supporting role in the housing project; the replacement of IRSAM by IRC after the suspension of the operation of IRSAM by the Monegasque authorities in October 1993 and the withdrawal of the Russians from the housing project as a result of the injunction.  See para 3 and 6 of Mr Leiduck’s 3^rd affidavit; para 34 of Mr Leiduck’s (2^nd) 5^th affidavit; para 5‑7 of Mr Leiduck’s 6^th affidavit; para 15‑21 of Mr Leiduck’s witness statement and para 5 of Mr Leiduck’s supplemental witness statement.

29.  Third, in support of IRC’s claim for loss of the value of its business or his own alternative claim for loss of opportunity to sell his IRC shares, Mr Leiduck deposed to how he founded IRC in 1972 and developed and expanded its business over the years until about 1993 when he became desirous of devoting his time and energy to building his business in Eastern Europe and started to explore the possibility of either selling 70% of his IRC shares to Yip or disposing of all his IRC shares to two Russian gentlemen surnamed Temerko and Mukhin.  According to Mr Leiduck, with Yip, he had only got to the stage of eliciting an expression of interest from Yip but they had not agreed on or even negotiated any details.  With the two Russians, Mr Leiduck had indicated to them that he was looking for something in the region of US$30 million.  Further, Mr Leiduck had also been told by his son, Mr Helge Leiduck (“Mr Leiduck Jr”), between 28 July and 27 September 2011 that Mr Leiduck Jr had been in negotiation with a Russian company called Stern‑Stroy Limited for a sale of 70% of Mr Leiduck’s IRC shares for US$20 million plus a promise of additional investment of up to US$40 million in IRC.  Mr Leiduck also asserted the belief that if it had not been for the injunction, he would have sold his IRC shares (which were worth US$30‑40 million), or a substantial portion thereof, to one of these 3 potential buyers.  See para 2‑26, 33 and 35‑39 of Mr Leiduck’s (2^nd) 5^th affidavit; para 10‑14 of Mr  Leiduck’s 1^st witness statement and the first answer of Mr Leiduck’s answer to interrogatories.

Circumstances under which Competency Issue Arose

30.  The court received Mr Leiduck’s written evidence and further heard his oral testimony while being unaware that:

(1)  On 7 July 2011, following a report by Mr Leiduck’s wife of incidents of visual hallucinations (some scenic) and disorientation, a Dr A Gallard, a specialist in neurology, had diagnosed Mr Leiduck to be suffering from dementia with Lewy‑bodies (“DLB”).

(2)  On 3 January 2012, a Dr F Sondhauss, a consultant/specialist for psychiatry and psychotherapy, had made psychological findings of, inter alia, erratic and long‑winded thought processes, reduced attention and concentration, impaired long term memory, paranoid thoughts, misperceptions in the form of visual hallucinations and impaired relation to reality and diagnosed Mr Leiduck to be suffering from moderate dementia. 

31.  As it turned out, Mr Leiduck did not complete his evidence in re‑examination. On 22 August 2013, before Mr Leiduck resumed his testimony under re‑examination, Mr Wong SC handed up to the court the English translation of a medical report dated 12 June 2013 (“Stein Report”) by a Dr Albrecht Stein which:

(1)  was commissioned by the court in Augsburg, Bavaria, Germany as a result of Mr Leiduck’s unwillingness and inability to testify in certain criminal proceedings against a third party;

(2)  addressed the question “whether Mr Leiduck is able to make a statement as a witness” in terms of his abilities to reasonably express his interests during the court room proceedings, to formulate his statement as a witness in a comprehensible manner, to answer specific questions of the parties in the case adequately and truly, to follow court proceedings adequately, to meet the obligation to tell the truth, to understand questions and statements of other parties in the proceedings and to adequately and actively assert his own legal interests;

(3)  noted that Mr Leiduck was suffering from dementia and cerebral‑organic psycho‑syndrome and taking medication for dementia (exelon); and

(4)  concluded that Mr Leiduck was then completely unable to participate as a witness in court proceedings, with no prospect of recovery.  In particular, it was said, inter alia, that Mr Leiduck had considerable deficiencies in both long and short‑term memory; that due to the considerable reduction in his memory function, particularly the long‑term memory, he could not be questioned “responsibly” on things that happened many years ago; that many experiences were increasingly processed by Mr Leiduck in a delusional manner as a result of his advanced age and the illness pattern of dementia and the cerebral‑organic psych‑syndrome which would only intensify; and that he could no longer answer sophisticated questions which went beyond his personal situation in a manner which was adequate and met his obligation to tell the truth.

32.  In addition to the Stein Report, Mr Wong SC also mentioned that Mr Leiduck had been examined by some other doctor though counsel was then not in a position to provide any meaningful detail.

33.  The trial was adjourned to 28 August 2013 for the defendants to make full and proper disclosure of all the information that they had at hand regarding Mr Leiduck’s mental health and capacity and for both parties to consider the implications of such information on the status of the evidence already given by Mr Leiduck and prepare submissions on what the court could and should do in the circumstances.

34.  By the 1^st affidavit of Mr Jeremy Levy of Robertsons (“Robertsons”), solicitors for the defendants, made on 23 August 2013, the defendants exhibited two other medical reports on Mr Leiduck compiled on 11 June 2013 and 13 August 2013 (“Pfeffer Reports”) by a Dr Klaus‑Dieter Pfeffer, a specialist in psychiatry and psychotherapy, following examinations of Mr Leiduck on 7 June and 9 August 2013 and which concluded that Mr Leiduck was “legally incompetent, incapable of being questioned and unfit to face proceedings in view of his cognitive and emotional disturbances as well as his physical impairment”.

35.  By the resumed hearing on 28 August 2013, it was recognised by all concerned that the contents and conclusions of the Stein Report and the Pfeffer Reports put into question Mr Leiduck’s fitness both as a party and as a witness.

Competency Issue Directions

36.  On 5 November 2013, I appointed Mr Leiduck Jr as next friend for Mr Leiduck for the purpose of carrying on these proceedings on Mr Leiduck’s behalf, thereby dealing with Mr Leiduck’s fitness as a party.  After Mr Leiduck’s death, by an Order dated 9 April 2014, Mr Leiduck Jr was appointed to represent Mr Leiduck’s estate in this action and to carry on this action on behalf of Mr Leiduck’s estate.

37.  On 5 November 2013 and subsequently on 8 November and 3 December 2013, with a large measure of agreement between the parties, I also gave and revised directions (“competency issue directions”) for assessing Mr Leiduck’s competence as a witness.

38.  More particularly, pursuant to the competency issue directions and by a joint letter of instructions dated 27 December 2013 from the parties’ solicitors (settled by the court failing full agreement between the parties), Dr Förstl[11] was appointed as joint expert to assess Mr Leiduck’s mental condition at the various times material to the competency issue.

39.  By his report dated 24 March 2014 (“1^st Förstl Report”) and oral evidence in court on Days 38‑40 (14‑16 April 2014), Dr Förstl expressed the views:

(1)  that Mr Leiduck was incompetent on 30 January and 9 February 2014 when he was examined by Dr Förstl;

(2)  that Mr Leiduck would not recover from such state of incompetence;

(3)  that there is no sufficient medical evidence reliably pointing to Mr Leiduck being of “unsound mind” before the diagnosis of DLB in July 2011;

(4)  that Mr Leiduck was incompetent in the relevant sense on all the occasions on which he gave oral evidence, save for the 8 May 2013 session;

(5)  that there is no sufficient evidence pointing to whether Mr Leiduck was competent or incompetent when he made his various affidavits and witness statements etc after July 2011.

40.  At the conclusion of Dr Förstl’s evidence in court on 16 April 2014, Mr Yan SC applied for leave to adduce additional expert medical evidence from Professor Felice Lieh Mak (“Prof Lieh Mak”)[12] on the competency issue, more particularly, Mr Leiduck’s competence or otherwise prior to February 2013.  In this regard, Mr Yan SC had, on 14 April 2014 before the commencement of Dr Förstl’s oral evidence, handed up a report dated 14 April 2014 by Prof Lieh Mak (“1^st Lieh Mak Report”) which expressed the contrary opinion that Mr Leiduck had become incompetent from as early as 2008 and remained so throughout the material times up to January 2013.

41.  I heard the application on 17 April 2014.  For the reasons set out in the decision handed down herein on 22 April 2014, by an order dated 25 April 2014, I gave the plaintiff leave to adduce expert evidence from Prof Lieh Mak on whether Mr Leiduck was incompetent on the various dates from 7 January 2008 to 28 January 2013 when he signed affidavits, witness statements, statements of truth verifying the defendants’ pleadings and answers to interrogatories.

42.  By an order dated 12 December 2014 made by consent, I gave the defendants similar leave to adduce expert evidence from Prof Helen Chiu Fung Kum (“Prof Chiu”)[13] on the same issues in response to Prof Lieh Mak’s reports.

Test of Incompetence

43.  I have already set out the text of s 3(b) of the EO in para 4 above.  There is no direct local authority on the meaning of section 3(b).[14]  English cases do not assist given the different tests for competence.[15]

44.  In response to Dr Förstl’s request for clarification of the meaning of incompetence under section 3(b), by Robertsons’ email dated 25 February 2014 to Dr Förstl, it was explained to Dr Förstl, inter alia, that a person falls within section 3(b) if and only if:

(1)  he is of unsound mind (which Dr Förstl called “criterion (1)” as a matter of shorthand in the 1^st Förstl Report); and

(2)  by reason of his being of unsound mind, he appears incapable of

(i)  receiving just (in the sense of “right”, “proper” or “correct”) impressions of the facts respecting which he is examined (“criterion (2a)”); or

(ii)  relating such facts truly (“criterion (2b)”).

45.  That is to say, a person is not incompetent simply by reasons of his having any particular mental illness or condition, unless he thereby appears incapable of receiving just impressions of the facts respecting which he is examined or of relating such facts truly.

46.  Dr Förstl understood (correctly in my view) section 3(b) to be triggered if criteria (1), (2a) and (2b) are met in the following ways: (1) and (2a) are true; or (1) and (2b) are true; or (1) and (2a) and (2b) are true.

47.  With this understanding, in respect of each the 3 criteria, Dr Förstl looked for and considered:

(1)  criterion (1) (“unsound mind”): the diagnosis of DLB or evidence of other significant neuropsychiatric disease;

(2)  criterion (2a) (“incapable of receiving just impressions”): evidence of impaired recollection and comprehension of facts, more specifically, facts respecting which Mr Leiduck was examined; and

(3)  criterion (2b) (“incapable of relating facts truly”): evidence of impaired ability to present those facts.

48.  In fact, Robertsons’ email dated 25 February 2014 to Dr Förstl was settled by me, failing agreement between the parties.  In doing so, I was provided with, and I duly considered, the parties’ solicitors’ respective draft replies to Dr Förstl which in effect contained the parties’ submissions on the proper construction of section 3(b).  In other words, Robertsons’ email dated 25 February 2014 to Dr Förstl, as settled by me, in effect contained my ruling on the meaning of section 3(b).  Given the fundamental importance of providing the expert with accurate guidance on the statutory test of incompetence, if I were wrong, I would expect both or either of the parties to demand an oral hearing at which further and/or more detailed arguments could be made by the parties, following which I would rule on the issue.  If I were still considered wrong, I would expect either or both of the parties to try to set me right by an appeal to the Court of Appeal.  As it were, neither party expressed disagreement with the reply to Dr Förstl that I settled. 

49.  I therefore did not anticipate:

(1)  the embellishment now sought to be placed by the plaintiff on the test of incompetence under section 3(b) as it applies to Mr Leiduck’s pre‑trial written evidence that was not contained in B&M’s draft reply to Dr Förstl; or

(2)  the resurrection by the defendants of a submission which was made in Robertsons’ proposed reply to Dr Förstl, which I had considered and dismissed.

50.  For the plaintiff, Mr Yan SC read section 3(b) of the EO with the following emphases:

“The following persons only shall be incompetent to give evidence in any proceedings‑

...

(b) persons of unsound mind, who, at the time of their examination, appear incapable of receiving just impressions of the facts respecting which they are examined or of relating them truly; and no person who is known to be of unsound mind shall be liable to be summoned as a witness without the consent previously obtained of the court or person before whom his attendance is required.”

51.  Mr Yan SC argued that:

(1)  affidavits/affirmations and witness statements are not per se admissible as evidence of a witness in a trial, without the attendance, adoption and oral examination on oath of the deponents/witnesses in open court.  See Order 38, rule 1.

(2)  The word “examination” in the phrase “at the time of their examination” in section 3(b) refers to cross‑examination. 

(3)  Reading section 3(b) as a whole and construing its words (especially the phrase “at the time of their examination” and the other words emphasised by the plaintiff as shown in para 50 above) in context, the test of competence in section 3(b) does not apply to competence to provide written evidence but requires competence to give evidence as a witness in court and be subject to examination in court, by which counsel means cross‑examination.

(4)  Hence, in determining whether Mr Leiduck was incompetent as a witness on any particular date on which he signed an affidavit/witness statement, the test is whether he was incompetent assuming he was cross‑examined in court on that particular day, and not his competence to produce written evidence or to sign documents.

(5)  Mr Leiduck’s competence on each of the subject dates between January 2008 and January 2013 must therefore be assessed on the assumption he was to be cross‑examined in court on those dates.

52.  The plaintiff advanced this submission (which was not included in B&M’s draft reply to Dr Förstl on the statutory meaning of incompetence) to take advantage of some of the answers given by Dr Förstl during the following line of cross‑examination by Mr Yan SC on 15 April 2014:

“Q: So if you had been asked in 2012 whether Mr Leiduck should be allowed to be, or allowed to testify, you would still be — even if you had known that he had this great drive and great mission in life, you would have been very uncertain whether or not he would have performed well?

A: Yes. And I would have —

Court: By performing well you mean whether he would be competent?

A: Could really stand trial without serious frustration, right from the beginning. That would have been a cause for my hesitating to recommend that he should really do it. On the other side, that is what he wants to do and it has an almost therapeutic quality for him to pursue that matter. So I would have been torn.

Court: That's not what we are interested in finding out. I think that the question is not whether he would find the experience satisfying or frustrating, but whether he would be able to give admissible evidence. So again, we go back to the two criteria under the Evidence Ordinance.

A: You see me as a medical expert for the court. I saw myself as the doctor who has to give advice, is it healthy for him to pursue that matter or not?

Court: No, you advising the court. Not the patient, whether he should risk suffering further frustration by giving evidence in court. You are advising the court whether the court should accept his evidence as being given by a person who is competent to do so.

A: Had I been consulted as an expert for the court —

Court: In 2012.

A: ... by 2012, I would have made an attempt to explain that it will be very hard to deal with this patient properly in court, and that one has to approach him very carefully and with great sympathy, and that sessions should be shorter. So that he would have had to be handled with care. That is what my advice would have been. And I assume that had the written evidence already been available, I would have probably told the court there is nothing else to be gained from a video interview. Because I would have doubted in the patient's stamina and ability to perform during lengthy and repeated interviews. Speculation.

Q: Because you would have felt that if he had been tested and challenged, then he wouldn't be able to perform competently?

A: Yes. To perform as well, and add anything useful to the written material.

Court: Because of a deficiency in his verbatim memory?

A: Indeed.

Court: He wouldn't be in a position to add to his witness statements?

A: Yes. Obviously, one wants to get a picture of the person, and for that reason, I understand that it can be very important to really meet him perhaps also via a video interview, to have an impression who that person is, how decent, how serious he is. But that would have been the purpose of these encounters and not his cross‑examination about details in 1993, 1994.

Court: But the purpose of cross‑examination was for the court to make a finding as to whether his written evidence is true or not.

A: I understand.

Court: So are you saying that you would not advise the court to allow him to be cross‑examined because you think that he had by then become incompetent?

A: I would have assumed‑

Court: What, in the technical sense that we are talking about?

A: I would have assumed that under these difficult and challenging circumstances, nothing useful would come of it. Neither corroborating nor invalidating what has already been available and written on paper. So I think, had you known about the patient's dementia, you would have wanted to see him, meet him, have an impression, but you would probably also have abstained from very critically questioning him on certain details that he was no longer able to reproduce without any personal support, without any aid from written or other material.

Q: Shall we put it a slightly different way; if you had been asked in 2012, without seeing the results of the oral examination, but seeing everything else; the nurses' reports and so on, if you had been asked then: ‘Can this person be subject to normal cross‑examination before the court?’ What would your answer have been?

A: My answer would have been no, not to normal cross‑examination. But if you agree on a different modality, if that would have been possible, I think I would have said yes. I understand it is important for the court, both sides to meet the patient acoustically, visually, to have an impression. But it is for your information‑

Q: Assuming that there could not have been special arrangements made to accommodate him.

A: Yes.

Q: And he would be subject to the same strenuous cross‑examination that he was subject to that you saw. Would you have said that he would not be competent to testify?

A: I would have advised against it, feeling that under these circumstances, it may give a wrong impression and not really — I’m repeating myself now. Not really adding to what was already there and available. I understand that for court, somebody who is so difficult to interview gives a negative impression. And a quite an impressive, bold, a proud person, how astounding at his age, he has such ideas and still stands his ground. But then over the course of the interviews, this impression was not an altogether positive one, I guess. He was scolded and admonished, at least, and he could not even on certain occasions — probably made the impression he did not want to accept what he was being told about how to answer the questions. And then there were more and more moments — for example, this is a temporary situation, that he did not understand that you were warning him. And I guess during that period, you felt this is not an ordinary interview. It is a very special situation. That was then confirmed by medical evidence.

Court: But was it difficult, or was the cross‑examination difficult for him because he had by then lost his ability to receive correct impressions of events, facts and circumstances?

A: Yes, I think lost the ability to master his cognition, or to gain access to the events, the details that he needed to speak about. He had lost the ability to speak about it precisely, and that altogether did not give a positive impression, I feel. But I have no way to compare with other video interviews and protocols of that kind. It may be that even under other circumstances, similar situations arise and they are not so infrequent and not so specific for the patient and his situation we are dealing with right now. It is your experience, not mine. Perhaps even non‑demented individuals get challenged to such an extent that they reach their limit in the course of a 120‑minute video interview or during other hearings.

Q: What about, say, in July 2011. If by that point in time, you had Dr Galland's report and you had the reports from his wife about him being disoriented. Had the court asked you whether this patient would be fit to be cross‑examined in the same way that he was cross‑examined in 2013, what would you have said?

A: Well, so then I would have been very cautious and I would not have recommended it to a patient with dementia with Lewy‑bodies. With the understanding how important it is for Mr Leiduck and knowing that it is a very changeable condition I would have said, yes, why don't you — or provide the written evidence and add to the written evidence. But I would not have encouraged him really to undergo video interviews.

Q: Well, this is a question not from the perspective of the patient, but from the court. If the court had asked you in July 2011, ‘Is this a person who should be subject to cross‑examination in a court?’, what would you have said?

A: I would probably have said no.

Q: Thank you.

A: Not if this is an important part of the hearing of the trial. I would have probably have advised against it. Probably.

Q: Yes.

Court: Dr Forstl, you said a moment ago you wouldn't have recommended Mr Leiduck to be cross‑examined in court, but you would have recommended him to provide his evidence in written form.

A: Yes.

Court: Why is there a difference, depending on the form in which he gives evidence? If he had lost the ability to comprehend facts correctly and to relate facts truly, then certainly it would apply equally to his written evidence?

A: Your Ladyship, patients with changeable conditions, fluctuations, can use the better periods to do very useful tasks. But if a fixed timeframe is given, offered that he has to sit for the video interview between 10 and 12 on this or that day, he may not be in the right frame of mind just during this predefined‑

Court: This goes back to your point that he suffered, he suffered a form of dementia which fluctuated, so that as long as he gave instructions and prepared his written evidence during a period of normality, then that piece of evidence would not have been affected by his incompetence.

A: Yes.

Court: Because what we don't know is whether the affidavits and the written statements that we are concerned about were prepared during such periods.

A: Yes. That is what we need to assume if we assume that he has done it by himself or almost only by himself, and as discussed yesterday, there are reasons to assume that the largest part of the important parts, or most of it, is really drafted by himself.

Q: Yes, you would need to make two assumptions, wouldn't you? You would need to assume that he had drafted those affidavits, and you would also need to assume that he had drafted them in a moment of competence before you could confidently say that the court, or anyone, can rely on the contents of these affidavits.

A: Yes.

Q: Would that be correct?

A: That would be correct. So I was only looking for the evidence of incompetence.

Q: Yes, yes, I accept that.

A: You mentioned yesterday that there is so much Mr Leiduck Senior, writing the same person who is speaking. He uses the same ideas. He sometimes uses exactly the same phrasing, et cetera. And even during his oral interviews, he does indeed refer to what has been written in the affidavits. He doesn't always refer to that evidence accurately, to that material accurately, but the gist, of course, there is one line, one firm message. The harm that has been done to him and family.

Q: Yes.

Court: So dealing with his oral evidence. You wouldn't have — well, in 2011, 2012, you wouldn't have recommended the court to accept Mr Leiduck's evidence in cross‑examination unless his evidence could have been taken in a different way, unless we could all sit in the court and wait for a normal interval in his condition and question him during that time.

A: Yes.

Court: Is that what you're talking about?

A: Perhaps it would have been possible to ask a few introductory questions, about the weather, about the date, how his morning was, to get an impression about the mood he is in. You have done that informally on several occasions and your impression was not a negative one. Perhaps Mr Leiduck could have been, would have agreed to take a certain memory test before one starts asking the more difficult questions about remote events, et cetera, because that would probably have been changeable from interview to interview. Perhaps he would have agreed on that. I'm not sure whether this would be a way to go about this. And then, of course, I would have recommended that if you wanted — you cannot test his verbatim memory reliably. This will just not be possible. What you can get is a better picture of the person. And if the conversation about the background story would have been a friendly one and not a controversial one, perhaps more could have been gained. A more proper impression of the person could have been gained. I understand that this is not the way things are going under normal circumstances.

Q: But, Dr Forstl, even if one had adopted the approach you suggested, of giving him a memory test, at the beginning of every session, even if he had passed the memory test when he was first asked and when he first took the test, halfway through the interview he could have lost it as well.

A: You're right, yes.

Q: Thank you. Now, what if you had been asked in 2010 then?

A: Under which circumstances would I have been asked? I'm not a specialist for cardiovascular medicine. I could have encountered the patient during a confusional state and I could have seen him then. Perhaps that would have been reason enough for me, as I’m particularly interested in these diseases, to do a more extensive cognitive test, explaining to the patient, Mr Leiduck, that he might benefit from that. Because we can use medication to improve his cognitive performance at that time.

Q: But again, would you have been confident that he would have been competent throughout the period when he was cross‑examined?

A: Mr Leiduck had been admitted repeatedly in critical condition, also temporarily affecting his mind, his cognitive performance. I would not have been sure whether a situation like this would not have distressed him so badly with his cardiovascular disease, that a good outcome to the advantage of Mr Leiduck would have been expected. I think I would have been cautious as his doctor.

Court: How about as the court's expert?

A: As the court's expert, I would have said, yes, it's a confusional state. I have not found sufficient evidence in my cognitive test that there is a dementia. If it is a confusional state, it will simply pass. And during the interval, why not?

Q: And in 2008‑2009? If you had been asked?

A:  There were also periods of confusion and they are temporary, and if it's not too much stress for his heart, I would have said yes, it is possible.”

53.  According to Mr Yan SC, as Dr Förstl accepted that Mr Leiduck could not be subjected to the stress and challenges of a normal cross‑examination (whatever that may mean!) before the court in 2011 and 2012 and was equivocal as to whether Mr Leiduck could do so in 2008, 2009 and 2010, Mr Leiduck was not competent to provide written evidence either during those years.

54.  Mr Yan SC is essentially asking the court, before holding Mr Leiduck competent on the occasions between January 2008 and January 2013 when he provided written evidence, to require Mr Lieduck to be capable of withstanding a fictional cross‑examination in court, in addition to being free from any unsoundness of mind that made him appear incapable of receiving just impressions or giving true accounts of fact.

55.  Neither of the authorities cited by Mr Yan SC, properly read, supports this proposition.

(1)  R v Powell[2006] 1 Cr App R 31was concerned with a very young child who gave her evidence‑in‑chief through a pre‑recorded interview and was then cross‑examined orally before the court.  The evidence‑in‑chief through the pre‑recorded video indicated that the child just about passed the competence threshold under section 53(3) of the 1999 Act.  The discussion by Scott Baker LJ at para 33‑42 of the judgment of the English Court of Appeal, relied on by Mr Yan SC, dealt with the largely abortive attempt at cross‑examination in court.  The statement in para 33 that what is relevant is the complainant’s competence to give evidence at the time of the accused’s trial, to which my attention has been specifically drawn, has to be understood in this light.  I agree with Mr Wong SC that the case is therefore no authority for the proposition that assessmentof the competency of a witness in giving written evidence out of court at a time earlier than trial would have to be made by reference to a hypothetical oral examination that was never made or required of him. 

(2)  R v Chan Kin, supra,is again a case that concerned oral evidence given in court (by girls who were mentally challenged).  It has nothing to do with written evidence given outside court before trial.  Mr Yan SC sought to derive support from p 3 of the judgment.  However, as noted in footnote 14 above, the Court of Appeal was there dealing with how a judge who has been made aware that a witness about to give evidence suffers from some form of mental disability should proceed. 

56.  Free of authority, I have great difficulty with the plaintiff’s argument.

57.  The EO itself contemplates that evidence may be given orally or in writing.  See, for example, sections 9, 44 and 76(3).  Section 3 itself stipulates when a person is or becomes incompetent “to give evidence in any proceedings”, without distinguishing between oral and written evidence. 

58.  Indeed, there are many proceedings in which evidence is received entirely in the written form without any oral examination in court.  There can be no question that the written evidence to be used in these proceedings must not come from someone who is incompetent as a witness as defined in section 3(b).  There is plainly no place for an assumption of a fictional cross‑examination in court in proceedings that do not entail such a stage. 

59.  Section 3(b) provides in terms for a single test of incompetence (unsoundness of mind causing an appearance of inability to justly perceive or truly relate facts), without regard to the manner in which evidence is taken.  If the legislature had intended to treat oral and written evidence differently and to also require a witness who gives evidence in writing to be capable of standing up to an oral cross‑examination in court at the time when he signs his affidavit/witness statement, I would have expected such different treatment between oral and written evidence and additional requirement for competence of written evidence to be expressly spelt out in section 3(b), rather than being left to be inferred in the really convoluted manner suggested by the plaintiff.

60.  To my mind, there is no reason why the words “at the time of their examination” in section 3(b), on which Mr Yan SC placed particular reliance, need to be read as referring to cross‑examination in court only.  The examination of a witness at a trial takes place in three stages: examination‑in‑chief, cross‑examination and re‑examination.  This phrase is apt to be applied to all these three stages.  As I see it, it simply fixes the time at which a witness must not be incompetent. 

61.  Nowadays, the examination‑in‑chief of a witness in court routinely takes the form of confirmation by the witness of the contents and truth of the affidavits/witness statements made by him before trial.  Given that the stage of examination‑in‑chief is completed in two phases, for an affidavit/witness statement to be admissible as direct evidence, the witness must not be incompetent at the time when he is asked to affirm the content and the truth of the document in court.  In the event that the witness has by the time of the trial become incompetent as defined in section 3(b), his pre‑trial affidavits/witness statements may, in appropriate circumstances, be admissible as hearsay evidence provided that he was not competent at the time when he signed them.  It is only when the witness is shown to be incompetent within the meaning of section 3(b) both when he signed the affidavits/witness statements and when he is asked to verify them in court that such written evidence is inadmissible on the ground of incompetence.

62.  I reject the plaintiff’s submissions that Mr Leiduck’s competence to give written evidence is dependent upon his being able to handle a hypothetical cross‑examination in court at the time when he provided such written evidence and that Mr Leiduck’s written evidence was produced while being incompetent because Dr Förstl either found Mr Leiduck unable to, or was equivocal as to whether Mr Leiduck could, cope with such examination from 2008 to 2012.

63.  It follows that Mr Wong SC’s complaint that Mr Yan SC had, in breach of the rule in Browne v Dunn (1894) 6 R 67, failed to put to the three experts the necessity of imagining a hypothetical cross‑examination of Mr Leiduck in court in assessing his competency to produce written evidence has become academic.

64.  For the defendants, Mr Wong SC invited me to infer that the EO intends that the threshold level of competence required to escape the application of section 3(b) should be that commensurate with the intelligence expected of an ordinary seven year old child. 

65.  In making this argument, counsel referred to and relied on the repealed section 3(a) of the EO which rendered children under seven years of age incompetent to give evidence unless they appear capable of receiving just impressions of the facts respecting which they are examined and of relating them truly, thereby creating a rebuttable presumption of incompetence of a child under 7.  Section 3(a) was deleted with effect from 28 July 1995 to “improve the quality of the trial by focusing on the weight to be given to the child’s account and easing the decision‑making process”: R v Lam Chi Keung, supra,at 426E.

66.  Mr Wong SC reasoned that the effectively identical wordings of the tests of competence/incompetence in sections 3(a) and (b) suggest that the threshold for person of unsound mind should also be at the same level, i.e. the level of a seven year old child of ordinary intelligence.  And the abolition of section 3(a) did not raise this threshold as far as persons of unsound mind are concerned “as section 3(b) has remained unchanged (if not lower by reason of the apparent shift to focus on the weight rather than admissibility)”.

67.  I had rejected the defendants’ invitation to read into section 3(b) a threshold level of intelligence by refusing to adopt the part of Robertsons’ draft reply to Dr Förstl that made the same point.

68.  Mr Wong SC did not produce any authority supporting the correlation between sections 3(a) and (b) suggested by him, which I find to be non‑existent.

69.  First, had the legislature intended “intelligence” of any level to be a material factor in determining the competence/incompetence of a person of unsound mind, one would have expected some hint of this in section 3(b) which, however, makes no such reference at all.

70.  Second, it is clear from section 3(b) (and likewise the repealed section 3(a)) that the ability/inability of a witness of unsound mind to justly perceive or truly relate facts is not to be assessed in abstract but with reference to the matters respecting which he is examined.  Section 3(a) was concerned with child witnesses and matters respecting which such witnesses are examined.  The old rebuttable presumption that a seven year old child is competent to give evidence must thus be viewed in the context of the matters respecting which a child witness may be examined. 

71.  In this connection, one just has to look at the relevant written evidence given by Mr Leiduck as summarised in paras 27‑29 above.  I simply cannot see an average seven year old child even of ordinary intelligence receiving an impression, or giving an account, of matters of the nature and complexity dealt with by Mr Leiduck.

72.  I have no hesitation in rejecting the defendants’ invitation to read into section 3(b) a threshold level of “intelligence” once again.

Burden and Standard of Proof

73.  Section 3(b) itself is silent on the incidence of the burden of proving whether a witness is or is not a person of unsound mind who appeared incapable of justly receiving or truly relating facts.  In this connection, I am unable to accept Mr Wong SC’s suggestion that the section implicitly places on the party alleging incompetence the burden of proving the same because it chooses to provide for what constitutes incompetence and not what constitutes competence. Given that the purpose of section 3(b) is to prevent incompetent persons from giving evidence, it is natural for incompetence (rather than competence) to be defined.  How else should the section be worded?

74.  Mr Wong SC for the defendants sought to attribute to the plaintiff the burden of proving the conditions of incompetence under section 3(b), principally on the basis that there exists a presumption that everyone is competent to give evidence unless shown to the contrary. 

75.  In my view, whether there is a presumption of competence is neither here nor there. What Mr Wong SC has failed to demonstrate, either on authority or in principle, is that such a presumption operates to shift to the party disputing competence the burden of proving incompetence within the meaning of section 3(b).

76.  In this regard, Mr Wong SC referred to the following judicial statements:

(1)  Chan Chi v The Queen [1968] HKLR 61, per Hogan CJ at 64:

“... When the Judge in the court below formed the view that the witness put before him was not a child of tender years, an impression which was strengthened by the reply that he was 14 years old, we think the Judge was entitled, without further inquiry, to treat the witness as competent, and to take sworn testimony from him.”

(2)  The Queen v Fung Kam Keung [1991] 1 HKLR 377, per Silke VP at 385H‑386B:

“Chan Chi referred to R. v. Horsburgh [1966] 3 Canadian Criminal Cases 240, where the Ontario Court of Appeal analysed the issue by dividing infant witnesses into four categories and, having done so, went on to state, as set out in Chan Chi at page 64:

‘The necessity for an inquiry arises only when the child witness is one of ‘tender years’.  The fact that some questioning did take place does not lead to the conclusion that the witnesses were of ’tender years’.  The brevity of the examination indicates to me that the presiding judge did not consider a more exhaustive examination necessary in order to determine that the witnesses were competent.  A child of 14 is presumed subject to conviction and punishment under the Criminal Code and in my opinion, a similar presumption must apply to the competency of such child to give sworn evidence.  An unnecessary enquiry does not defeat the presumption of competency unless the questioning actually elicits information which clearly shows that the child does not appreciate the nature or consequence of an oath.’”

(3)  R v Lam Chi Keung, supra, per Mortimer JA at 424I (after referring to the English provision which requires a child’s evidence to be received unless it appears to the court that the child is incapable of giving intelligible testimony):

“This seems to require that the competency of a child witness be judged in the same way as any other witness. But as Mr Ross points out — the Hong Kong legislation appears to provide that even a child who is unable to give intelligible testimony is competent if otherwise of sound mind. However, this last point did not arise at trial and cannot arise now. This witness was of sound mind and capable of giving intelligible testimony. Clearly, a child witness is to be regarded as competent at least unless the contrary is shown.”

77.  None of these cases were concerned with a witness of unsound mind in a civil case. They all involved child witnesses of sound mind for the prosecution in criminal proceedings and were concerned with determining whether a prosecution witness was of tender years and therefore unable to give sworn testimony.  The incidence of the burden of proving competence/incompetence of such a witness did not arise at all.

78.  At common law, in criminal cases, it is well established that once the issue of competence of a witness is raised, the burden is on the party calling the witness or seeking to have the witness sworn to satisfy the court that the witness is competent to give evidence in the proceedings: see R v Yacoob (1981) 72 Cr App R 313 (which was decided before the 1999 Act).  The criminal standard of proof (beyond reasonable doubt) applied in deciding issues of admissibility of the evidence of prosecution witnesses (R v Ewing [1983] QB 1039) while the civil standard (balance of probabilities) applied to the evidence of the defence (R v Mattey [1995] 2 Cr App R 409).[16]  The rationale appears to me to be that the burden of proving the competence of a witness (when the same is in issue) and therefore the admissibility of his evidence should follow the burden of proving the facts sought to be established by that witness’ evidence.

79.  By parity of reasoning, I cannot think of any objection in principle why the same rule should not apply in civil cases: see Phipson on Evidence, supra, paras 9–12.  This is the only approach that is consistent with the general rule that the party who asserts must prove.  Where a party seeks to rely on a particular piece of evidence, and there is a dispute as to its admissibility, he should have the burden of proving that it is admissible (Phipson on Evidence, supra, para 6–04). The competence of a witness goes to the admissibility of his testimony.  Where the competence of the witness is put in issue, proving that the witness is not incompetent so that his evidence is admissible is really discharging the burden of proving the facts to which such evidence relates.  It follows that in civil cases the burden should also fall on the party calling a witness and relying on his evidence to prove that he is not incompetent under section 3(b) of the EO if this is disputed.

80.  In conclusion, the defendants have the burden of proving that Mr Leiduck was not at the material times incompetent as defined in section 3(b) by showing, on a balance of probabilities, that Mr Leiduck

(1)  was not of unsound mind; or

(2)  did not appear incapable (a) of receiving just impressions of the facts respecting which he was examined or (b) of relating them truly.

Such burden is only consistent with the defendants’ burden of establishing the matters sought to be proved by Mr Leiduck, the admissibility of which is conditional upon and Mr Leiduck’s competence.

81.  I now turn to the competency issue.

Materials before the Court

82.  In addition to the written evidence and transcripts of oral testimony listed in para 3 above, there are before the court 6 leverarch files of original and translated contemporaneous records kept by the independent medical and nursing professionals who cared for Mr Leiduck from November 2001 right up to his death on 23 March 2014.

83.  These primary materials were reviewed by the three expert witnesses who between them produced a total of seven reports of about 300 pages citing reference materials which take up another three full leverarch files:

Date	Expert	Report
24.3.2014	Dr Förstl	1st Förstl Report
14.4.2014	Prof Lieh Mak	1st Lieh Mak Report
19.5.2014	Prof Lieh Mak	2nd Lieh Mak Report
8.2014	Dr Förstl (commenting on the 1st & 2nd Lieh Mak Reports)	2nd Förstl Report
3.9.2014	Prof Chiu (commenting on the 1st & 2nd Lieh Mak Reports)	Chiu Report
13.1.2015	Prof Lieh Mak (commenting on the 2nd Förstl Report)	3rd Lieh Mak Report
13.1.2015	Prof Lieh Mak (commenting on the Chiu Report)	4th Lieh Mak Report

84.  The 1^st Förstl Report also set out the information provided to Dr Förstl by Dr Christine Funk (the general practitioner who looked after Mr Leiduck since his move to the second nursing home in Starnberg‑Percha in April 2013), Dr Pfeffer (a specialist for psychiatry and psychosomatics and the author of the Pfeffer Reports), Mr Leiduck Jr and his wife (Ms Herlinde Leiduck), Dr Linda Koiran (Mr Leiduck’s daughter), Dr med Lother Schumann (Mr Leiduck’s wife’s cousin and Mr Leiduck’s long‑term friend and himself an orthopaedic surgeon) and Mrs Schuman.

85.  It also contained Dr Förstl’s report on his personal examination of Mr Leiduck on 30 January and 9 February 2014.

86.  The three expert witnesses were examined in court for a total of 20 days.[17]  Dr  Förstl and Prof Chiu on one hand and Prof Lieh Mak on the other held contradicting views, and were cross‑examined in the most comprehensive fashion by Mr Yan SC and Mr Wong SC, on numerous points, some of which have, with the benefit of hindsight and in the light of the parties’ final positions in closing submissions, become of peripheral importance (save that a conclusion one way or another may perhaps function in generating an impression of the general reliability of the witnesses) or even altogether immaterial, to the real questions that I have to decide.

87.  In addition to the aforesaid primary factual evidence on Mr Leiduck’s mental condition and the opinion evidence given by the three experts on the basis of such primary factual evidence, I also have the benefit of the parties’ closing submissions, made both in writing which add up to close to 500 pages (not counting appendices and authorities) and orally in court which took three full hearing days.[18]

88.  I am indebted to counsel for their thoroughness in both evidence and submissions, all of which I have duly reviewed and considered with care.  I am well aware of all the differences between the parties, put to the witnesses in cross‑examination and addressed in closing submissions.  With no disrespect to counsel, I do not propose to attempt to resolve every such difference.  It is unnecessary for me to do so.  To maintain the focus of this judgment, I hope I would be forgiven for dealing only with those matters that have a material effect on the findings that I have to make.

Summary of the Experts’ Opinions

89.  I have been reminded by Mr Yan SC, and I bear in mind, that:

(1)  The question of the capacity of a witness is a question of fact (R v Reynolds [1950] 1 KB 606), the determination of which is a matter for the court and not for the expert witnesses.

(2)  While the court should not form its own expert theory or adopt a specialist position not posited to it by any expert (see Hodgkinson, Expert Evidence Law & Practice, 4^th Edition, para 12–007), it is open for the court to make findings contrary to opinions of the experts (even where their reports are agreed).

(3)  In the final analysis, facts are always predominant as they are what the party must prove or disprove, and expert opinion evidence only serves to provide the court with the necessary specialist framework to enable it to form its own independent judgment in the assessment of the facts proved in evidence.

(4)  The evidence of all three experts should be considered on an equal footing. 

(5)  The court does not have to accept the evidence of Dr Förstl, although he was appointed by the court as a joint expert, and must take its own view of such evidence in light of all the other factual evidence available (see Coopers Payen Ltd v Southampton Container Terminal Ltd [2004] 1 Lloyd’s Rep 331 (CA), per Clarke LJ at para 41–43, applied in L v L, HCMC 1/2003, unreported, 20 April 2005, per Lam J at para 10).

90.  Nevertheless, the experts’ conclusions provide a useful starting point.

Dr Förstl

91.  According to Dr Förstl:

(1)  A diagnosis of DLB was first made on 7 July 2011 (see para 30(1) above) and the clinical diagnostic features of DLB (cognitive impairment with a great deal of fluctuations, occasional visual hallucinations and (mild) Parkinsonism) have been satisfied ever since.

(2)  Further, the cranial Computed Tomography (cCT) images recorded on the same day[19] showed clear evidence of severe vascular brain changes in Mr Leiduck, which is diagnostic for vascular dementia (“VaD”) (or a vascular contribution to cognitive impairment).

(3)  The correct etiological diagnosis is therefore mixed dementia with vascular and neurodegenerative brain changes (vide infra).

(4)  However, while some earlier medical reports mentioned suspicious symptoms, there is no sufficient medical evidence reliably pointing to earlier significant cognitive deficits or other relevant psychopathology that might account for “unsound mind” before July 2011.

(5)  Hence, criterion (1) (“unsound mind”) could not be satisfied for the period prior to July 2011.

(6)  However, even for the period after July 2011, Mr Leiduck did not have to suffer from signs of dementia everyday even if he had this disease (which was a type of brain change).  The course of both DLB and VaD, though downhill, is characterised by fluctuations, the amplitudes of which can be quite significant and drastic.  The patient may on some days be capable of performing quite well, not appearing to be demented at all.  On other occasions, especially under pressure, he may show clear signs of dementia.  Some of these fluctuations may even arise spontaneously.  They can occur within a matter of hours.

(7)  The typical changeability of these forms of dementia means that criteria (2a) and (2b) could be satisfied differently at different times and under different circumstances. Sitting in a familiar environment (like one’s own study) drafting, giving instructions for the preparation of, approving or signing a written statement with the assistance of an attorney and holding out during cross‑examination in a strange setting (like a court room or interview room) present different situational demands.

(8)  In this regard, Mr Leiduck’s mental state and competence had been significantly and almost constantly affected after his wife’s death on 3 February 2013 and became obvious with the beginning of his oral testimony on 25 February 2013.  Even then, remarkable changes — including occasional and transient recoveries — were to be observed between February and August 2013.

(9)  Therefore, each occasion on which Mr Leiduck gave evidence, and each piece of evidence given by him, has to be examined and evaluated individually.

(10)  Fully appreciating that it was not for him to examine the truth or falsity of Mr Leiduck’s evidence, Dr Förstl focused less on contents but more on the form of presentation.

(11)  He was satisfied that Mr Leiduck was incompetent in the relevant sense on all the occasions on which he gave oral evidence, save for the 8 May 2013 session.  He found in the transcripts of the examination of Mr Leiduck in court (which provide the most reliable evidence) proof of Mr Leiduck’s impaired recall (of names, dates and other detailed facts) from his verbatim memory and persistent resort to his gist memory.  Mr Leiduck was also verbose and at times incoherent and became unable to relate the facts properly when he did not take in the questions or directions or while he was occupied with his thoughts and intent on presenting his side of the story.

(12)  He however could not find in the transcript of Mr Leiduck’s cross‑examination on 8 May 2013 sufficient material pointing to fulfilment of criteria (2a) and (2b).

(13)  As for the evidence contained in Mr Leiduck’s various affidavits and witness statements etc, he could not find sufficient evidence upon which he could conclude whether Mr Leiduck was competent or incompetent when making them, even after 7 July 2011, because he did not feel able to assume, without reliable evidence, whether Mr Leiduck drafted, gave instructions for, approved or signed a particular written proof in a good or bad moment during the fluctuating course of his dementia.

Prof Chiu

92.  On Mr Leiduck’s competence on the subject dates between 7 January 2008 and 28 January 2013, Prof Chiu generally shared Dr Förstl’s views:

(1)  Before July 2011, there is insufficient evidence to diagnose Mr Leiduck as suffering from dementia.

(2)  After the diagnosis of DLB in July 2011, Mr Leiduck’s competence must be assessed on each occasion and incompetence cannot be inferred in the absence of clear evidence of dementia from January 2008 to the end of 2010.

(3)  Mr Leiduck was competent within the meaning of section 3(b) of the EO on the subject dates between September 2011 and January 2013.

Prof Lieh Mak

93.  Prof Lieh Mak on the other hand took the view that Mr Leiduck was suffering from DLB and VaD, and had therefore been incompetent as a witness, since as early as 2008.

Findings on the Competency of the Oral Evidence

94.  I accept Dr Förstl’s conclusion of incompetence regarding Mr Leiduck’s oral evidence, which is not disputed by either party.

95.  As for the 8 May 2013 session, it will be seen that I prefer Dr Förstl’s evidence (supported by Prof Chiu) as to the typical changeability of both DLB and VaD.  I see no reason to doubt Dr Förstl’s assessment that Mr Leiduck, though of unsound mind on 8 May 2013, did not appear to be incapable of receiving just impressions of facts or of relating them truly.

96.  Consequently, I find all of Mr Leiduck’s evidence in court, except that given on 8 May 2013, inadmissible on the ground of Mr Leiduck’s incompetence under section 3(b) of the EO.

Outstanding Issues

97.  What remains in issue is Leiduck’s competence or otherwise on 7 January 2008, 9 December 2008, 25 June 2009, 30 March 2010, 6 April 2010, 27 September 2011, 11 January 2012, 19 September 2012, 15 November 2012 and 28 January 2013 (leaving out the dates on which Mr Leiduck signed statements of truth of pleadings for the reasons explained in paras 7 and 8 above).

98.  More particularly, I have to decide:

(1)  whether Mr Leiduck had already become of unsound mind by virtue of DLB (or VaD) before being diagnosed by Dr Gallard in July 2011;

(2)  if so, since when Mr Leiduck became of unsound mind; and

(3)  whether his being of unsound mind on the subject occasions, if any, made him appear incapable of receiving just impressions of fact or of relating them truly.

My Overall Impression of the Experts

Dr Förstl

99.  Dr Förstl’s standing as a leading expert in both neurology and psychiatry with particular qualifications, expertise and experience in all kinds of dementia and age associated mental diseases, and his independence and impartiality as the court‑appointed joint expert, is beyond question and has never been questioned.  The department of which Dr Förstl is the director has, inter alia, a day care centre for elderly patients (with dementia, depression and other age associated mental diseases) and three outpatient clinics for organic mental diseases (dementia and mild cognitive impairment).  It has an excellent reputation in, among others, the area of dementia and frequently provides expert opinions on questions of mental capacity to families, lawyers and courts.  Dr Förstl is certainly familiar with the assessment of mental competence to be a witness, having been involved in the approval of approximately four opinions per year dealing with the question of mental competency to testify in court and the retrospective assessment of when a witness may have become incompetent.

100.  I have been greatly assisted by Dr Förstl.  The 1^st and 2^nd Förstl Reports were comprehensive and well grounded in analysis and reasons.  Dr Förstl’s evidence under cross‑examination in court (over six days) was visibly forthcoming and fair and inspired confidence.

Prof Chiu

101.  I have likewise benefited from reading the Chiu Report and following Prof Chiu’s evidence under cross‑examination in court (over five days).

102.  Prof Chiu is clearly respected locally and internationally in the fields of psychogeriatric (old age psychiatry) and dementia.

103.  More particularly, Prof Chiu holds/held, inter alia, the following esteemed professional positions:

(1)  Founding President of the Hong Kong Psychogeriatric Association;

(2)  Chairman of the Psychogeriatric Working Group which co‑ordinates the development of psychogeriatric services of the Hospital Authority;

(3)  Member of the Expert Group on Dementia set up by the Hong Kong Government;

(4)  Founding Director (2002–2004) of the Jockey Club Centre for Positive Ageing, a specially designed centre for dementia care;

(5)  Past President of the Pacific Rim College of Psychiatrists and the International Psychogeriatric Association (“IPA”)[20];

(6)  Member of the IPA Capacity Taskforce which deals with issues of mental capacity;

(7)  Member of the Medical and Advisory Panel of the Alzheimer’s Disease International; and

(8)  Editor of Asia Pacific Psychiatry and Member of the editorial boards of over ten journals including International Psychogeriatrics and International Journal of Geriatric Psychiatry.

104.  Prof Chiu served as Keynote or Plenary Speaker of various Alzheimer’s Disease International conferences.  She was recently invited to participate in the WHO First Ministerial Conference on Global Action Against Dementia.

105.  Prof Chiu has researched and published widely on dementia and is a pioneer in the research of dementia in Hong Kong, having carried out the first epidemiological study in dementia in Hong Kong in 1995.

106.  Not only is Prof Chiu an expert on dementia, she also has special experience in and knowledge of DLB, the sub‑type of dementia with which we are concerned under the Competency Issue:

(1)  She was invited to the International Psychogeriatric Association Meeting on DLB in 2002, and co‑authored with, inter alia, Prof Ian McKeith the review paper entitled “Dementia with Lewy Bodies” published in 2004 in Lancet Neurology, a high impact journal.

(2)  She is currently a member of the Consultation Group on the Classification of Behavioural and Psychological Symptoms in Neurocognitive Disorders, which is responsible for the recommendation of a classification system and standard descriptions for BPSD to be included in ICD‑11.  Amongst the 15 members of this group, there are about five psychiatrists and Prof Chiu is one of the only two psychiatrists from Asia.

(3)  She is professionally connected with the pioneering/leading researchers and experts on DLB including Prof McKeith, Prof Donaghy, Prof J O’Brien, Prof O’Neill etc whose authoritative papers were the main authorities cited and relied on in these proceedings.

(4)  In addition to research on dementia generally, Prof Chiu has further published papers specifically on DLB.

107.  Prof Chiu is, however, not just an academic, but an experienced clinician with ample first hand experience in treating dementia patients (including those with DLB) for about 25 years and has seen at least 1,500 patients.  In the past 3 years, she has treated over 200 dementia patients, 8 to 9 of which were suffering from DLB.  The latter figure should be viewed against the relatively low prevalence of DLB in Hong Kong (only about 3%).

108.  Prof Chiu effectively conveyed her vast experience and expertise in dementia generally and DLB specifically through her report and oral examination.  She was demonstrably familiar with the literature and researches on DLB and able to recall them in her head and discuss them in a relevant manner.  She managed to comment on, and provide responding authorities, to the new research materials produced by the plaintiff in the middle of her evidence within a day.  Mr Yan SC cautioned against the assumption that every patient and his disease progression will follow a “textbook” picture and criticised Prof Chiu for taking an overly academic approach in the assessment of Mr Leiduck. With respect, this is unfair.  The proof of facts on a balance of probabilities is not a subjective exercise.  In the assessment of mental health and capacity, the findings, opinions and conclusions obtained through specialised studies and researches acknowledged and accepted by the academic and medical communities should be invaluable in guiding the court in deciding where the balance of probabilities should inherently and objectively lie.  In any event, Prof Chiu never lost sight of Mr Leiduck as an individual and always took into account his peculiar personal circumstances.

109.  Further, despite her lack of prior experience as a court expert, Prof Chiu was not unfamiliar with the assessment of mental capacity, having been actively involved in the research, publication and discussions with other experts on issues relating to assessment of mental capacity over the years.

110.  On the whole, I find Prof Chiu a professional and knowledgeable expert witness who, though called by one side, is fair and true to the discipline that she practises.

Prof Lieh Mak

111.  I do not think it is unjust for me to say that Prof Lieh Mak is more of a generalist.  Dementia is admittedly not her specialty.  Her curriculum vitae does not reveal any specialised research or publication on dementia.  She saw only around 30 elderly patients in the previous three years with just 1 or 2 of them suffering from DLB (who were all at a very late stage of the condition).

112.  Of course, I appreciate that the evaluation of expert opinion evidence is not a comparison of the experts’ credentials.  However, I have come to the view that I should approach Prof Lieh Mak’s evidence with caution.

(1)  There were quite a number of fundamental errors in the four Lieh Mak Reports and in Prof Lieh Mak’s evidence in court (over nine days).  I adopt the examples identified by Mr Wong SC: that she used the non‑existent phrase “higher cognitive function” (instead of “higher cortical function”); that she seemed uncertain about, and gave different figures for, the cut‑off score of the Mini‑Mental State Test (“MMSE”) which is widely used in the detection of dementia; that she wrongly equated neurocognitive disorder (“NCD”) in para 16(b) of the 2^nd Lieh Mak Report with dementia when in fact only Major NCD corresponds with dementia and Minor NCD does not; that she erred in suggesting, and had to withdraw under cross‑examination her statement in para 16(b) of the 2^nd Lieh Mak Report, that in view of Mr Leiduck’s advanced age once brain cells die they are dead and new cells could not be generated or new connections made and had to later agree that neurogenesis does occur and new connections could be made for elderly people.

(2)  Prof Lieh Mak was less forthcoming than one would expect from an expert witness.  There were many instances in which the same question had to be repeated a number of times before Mr Wong SC could get a direct answer from Prof Lieh Mak.  Again, I adopt the examples listed by Mr Wong SC: the question whether Prof Lieh Mak had seen any patient who had systematised delusions that lasted for several years which was asked four times before Prof Lieh Mak said “no”; the question as to where she got the guideline on nursing care level which was asked four times before Prof Lieh Mak said she probably obtained it from the internet without actually identifying the source; and the question as to whether she had assumed that the records of the psychiatric consultations done during Mr Leiduck’s hospitalisation in May 2008 were records of one examination which had to be repeated even by the court before Prof Lieh Mak would answer in the affirmative.

(3)  Prof Lieh Mak’s positions on many key issues evolved and changed in the course of her oral evidence in such ways and to such extents that at least create the impression that the matters had not been well thought through.  Mr Wong SC has identified many examples in para 34(3) of his written submissions dated 6 May 2016.  I shall set out some of them:

(a)  Prof Lieh Mak came up with a new description of DLB as “dementia superimposed by the delirium” in the middle of her oral evidence, but then withdrew it when pressed.

(b)  She changed her description of the progressing course of DLB (as well as her hand demonstration) from a linear downhill course to a fluctuating downhill course.

(c)  As to what actually fluctuates in DLB, Prof Lieh Mak changed from her original position that only attention and alertness fluctuates to the later position that other domains of cognition do also fluctuate, but they are contingent upon fluctuation of attention and alertness.

(d)  She changed the nature of her “Top‑Down” theory from one based on brain structures to one based on functions.

(e)  Prof Lieh Mak changed her diagnosis for the year 2008 from Stage 1 DLB to dementia with unknown aetiology, and then to somewhere between Stage 1 and Stage 2 DLB.

(4)  It seems to me that many of Prof Lieh Mak’s conclusions were underpinned by assumptions that were wrong or groundless or not her place to make, for example:

(a)  Prof Lieh Mak assumed that Mr Leiduck’s case was factually false and that he must have been delusional in maintaining it.

(b)  She assumed that the delusions observed by Dr Pfeffer and Dr Sondhauss were of the same content as those contained in the evidence of Mr Leiduck in the present proceedings in support of her opinion that Mr Leiduck’s delusional theme was fixed and had lasted for many years.

(c)  Prof Lieh Mak “took it for granted” that there had been cognitive decline for six months before 2008 in order to justify her diagnosis of dementia in 2008 in satisfaction of the six months rule required by ICD‑10.

(d)  Prof Lieh Mak assumed that a lot of details were missing in Mr Leiduck’s written evidence because he could not remember them even though he wanted to put them in order to justify her opinion on his over reliance on gist memory.

(e)  Prof Lieh Mak assumed that Mr Leiduck’s reason for changing his mind in providing in his 2^nd Affidavit the name of Fink (which he deliberately withheld in his 1^st Affidavit as he had promised Fink to do so) must be because he did not appreciate the significance of his promise, in order to justify her conclusion that Mr Leiduck had difficulties in receiving just impression.

(f)  Prof Lieh Mak was inexplicably reluctant to review and reconsider her opinion upon being told that Mr Leiduck was in fact correct about the date of his release from prison in Monaco (in 1996) which preceded his conviction in Monaco (in 2000), a statement which Prof Lieh Mak assumed to be wrong and relied upon to attribute delusion to Mr Leiduck. Indeed, I had to remind her a few times that Mr Leiduck had not mixed up those dates.

113.  It is worthy of note that although Mr Yan SC objected to the observations that Mr Wong SC made with regard to Prof Lieh Mak’s quality, independence and integrity as an expert witness (e.g. that she “has shown herself to be an evasive, defensive, and biased expert”; that she was “constantly shifting ground when seeking to justify her opinion” etc), Mr Yan SC did not take issue with Mr Wong SC’s summary of the instances upon which he made those criticisms against Prof Lieh Mak.

114.  Indeed, I further observe that Mr Yan SC himself did not adopt many of the arguments made by Prof Lieh Mak in support of “unsound mind” in the years preceding 2011 in the closing submissions for the plaintiff.  In light of this, in the judgment that follows, I will not address all the arguments made by Prof Lieh Mak but shall focus on the plaintiff’s case with reference to the submissions advanced on its behalf.

115.  For the avoidance of any misunderstanding, despite my said impressions of the expert witnesses, I propose to resolve the material differences between them based on the relative merits of the arguments.

DLB

Diagnostic criteria

116.  The obvious starting point for making a diagnosis of DLB, be it contemporaneous or retrospective, must be the diagnostic criteria.

117.  In this regard, I do not see the point of Mr Yan SC’s observation that the diagnostic criteria were formulated for the purpose of the diagnosis of live patients rather than for retrospective assessment.  I do not see myself conducting a roving open‑ended inquiry into Mr Leiduck’s mental health.  The plaintiff disputes Mr Leiduck’s competence, after access to his medical records, on specific ground, which is that Mr Leiduck had been of unsound mind by reason of DLB ever since 2008, as retrospectively diagnosed by Prof Lieh Mak.  How else could I decide whether Prof Lieh Mak is right if not by reference to the diagnostic criteria?  Prof Lieh Mak herself claimed to have applied the DSM‑5 diagnostic criteria.  Mr Yan SC has produced no authority to the effect that the criteria for the diagnosis of DLB would be any different in a retrospective assessment.  Prof Chiu was clear that the diagnostic criteria for DLB are the same for both clinical assessment and retrospective assessment.

118.  There are currently two internationally accepted diagnostic criteria of DLB:

(1)  the “Consensus Criteria” as set out in the 3^rd report of the DLB Consortium in 2005; and

(2)  DSM‑5 at pp 618–620.

119.  The Consensus Criteria sets out the criteria for the clinical diagnosis of DLB as follows:

“1. Central feature (essential for a diagnosis of possible or probable DLB)

Dementia defined as progressive cognitive decline of sufficient magnitude to interfere with normal social or occupational function. Prominent or persistent memory impairment may not necessarily occur in the early stages but is usually evidence with progression. Deficits on tests of attention, executive function, and visuospatial ability may be especially prominent.

2. Core Features (two core features are sufficient for a diagnosis of probable DLB, one for possible DLB)

Fluctuating cognition with pronounced variation in attention and alertness

Recurrent visual hallucinations that are typically well formed and detailed

Spontaneous features of parkinsonism

3. Suggestive features (If one or more of these is present in the presence of one or more core features, a diagnosis of probable DLB can be made. In the absence of any core features, one or more suggestive features is sufficient for possible DLB. Probable DLB should not be diagnosed on the basis of suggestive features alone)

REM sleep behaviour disorder

Severe neuroleptic sensitivity

Low dopamine transporter uptake in basal ganglia demonstrated by SPECT or PET imaging

4 Supportive features (commonly present but not proven to have diagnostic specificity)

Repeated falls and syncope

Transient, unexplained loss of consciousness

Severe autonomic dysfunction, e.g. Orthostatic hypotension, urinary incontinence

Hallucinations in other modalities

Systematized delusions

Depression

Relative preservation of medial temporal lobe structures on CT/MRI scan

Generalized low update on SPECT/PET perfusion scan with reduced occipital activity

Abnormal (low uptake) MIBG Myocardial scintigraphy

Prominent slow wave activity on EEG with temporal lobe transient sharp waves

5. A diagnosis of DLB is less likely

In the presence of cerebrovascular disease evidence as focal neurologic signs or on brain imaging

In the presence of any other physical illness or brain disorder sufficient to account in part or in total for the clinical picture

If parkinsonism only appears for the first time at a stage of severe dementia.

...”

120.  The diagnostic criteria in DSM‑5, under “Major or Mild Neurocognitive Disorder with Lewy Bodies”,[21] read as follows:

“A. The criteria are met for major or mild neurocognitive disorder.

B. The disorder has an insidious onset and gradual progression.

C. The disorder meets a combination of core diagnostic features and suggestive diagnostic features for either probable or possible neurocognitive disorder with Lewy bodies. For probable major or mild neurocognitive disorder with Lewy bodies, the individual has two core features, or one suggestive feature with one or more core features. For possible major or mild neurocognitive disorder with Lewy bodies, the individual has only one core feature, or one or more suggestive features.

1. Core diagnostic features:

a. Fluctuating cognition with pronounced variations in attention and alertness.

b. Recurrent visual hallucinations that are well formed and detailed.

c. Spontaneous features of parkinsonism, with onset subsequent to the development of cognitive decline.

2. Suggestive diagnostic features:

a. Meets criteria for rapid eye movement sleep behavior disorder.

b. Severe neuroleptic sensitivity.

D. The disturbance is not better explained by cerebrovascular disease, another neurodegenerative disease, the effects of a substance, or another mental, neurological, or systemic disorder.” (original emphasis)

121.  The DSM‑5 diagnostic criteria were apparently based largely on the Consensus Criteria.  It can be seen that:

(1)  Criteria A & B effectively correspond to the Central Feature as defined in the Consensus Criteria;

(2)  Criterion C sets out the core diagnostic features and suggestive diagnostic features, as referred to in the Consensus Criteria with only one difference which is not relevant to the present case;

(3)  Criterion D is similar to para 5 of the Consensus Criteria.

122.  Apart from setting out the diagnostic criteria required to be satisfied for a diagnosis of DLB, DSM‑5 also reproduces the Supportive Features mentioned in para 4 of the Consensus Criteria under a different label namely, “Associated Features Supporting Diagnosis” which includes again similar features like repeated falls, syncope, systematized delusions etc.

123.  DSM‑5 further provides for the following diagnostic guidelines for Major NCD (equivalent to dementia under ICD‑10) at pp 602–603:

“A. Evidence of significant cognitive decline from a previous level of performance in one or more cognitive domains (complex attention, executive function, learning and memory, language, perceptual‑motor, or social cognition) based on:

1. Concern of the individual, a knowledgeable informant, or the clinician that there has been a significant decline in cognitive function; and

2. A  substantial impairment in cognitive performance, preferably documented by standardized neuropsychological testing or, in its absence, another quantified clinical assessment.

B  The cognitive deficits interfere with independence in everyday activities (i.e., at a minimum, requiring assistance with complex instrumental activities of daily living such as paying bills or managing medications).

C  The cognitive deficits do not occur exclusively in the context of a delirium.

DThe cognitive deficits are not better explained by another mental disorder (e.g. major depressive disorder, schizophrenia)”

124.  Mr Wong SC rightly observed that apart from one minor difference that has no bearing in the present case, these two sets of diagnostic criteria are effectively identical.

125.  In applying these diagnostic criteria, the “supportive features”under the Consensus Criteria or the “associated features supporting diagnosis” under DSM‑5are not part of the diagnostic criteria.  The mere presence of these features, however frequent or serious, would not warrant a diagnosis of DLB.  This should be spelt out because Prof Lieh Mak who applied DSM‑5 had included, in para 10(c)(E) of the 2^nd Lieh Mak Report,the “associated features supporting diagnosis”as part of the DSM‑5 diagnostic criteria.  Prof Lieh Mak accepted in her oral evidence that the features mentioned there (e.g. delusion) are not a diagnostic criterion of DLB.

126.  I have so far not mentioned ICD‑10 which does not contain any specific diagnostic criteria for DLB.  But it is not irrelevant as it does provide for the diagnostic criteria for dementia generally (which is the central feature for a diagnosis of DLB under both the Consensus Criteria and DSM‑5) as follows:

“Dementia is a syndrome due to disease of the brain, usually of a chronic or progressive nature, in which there is disturbance of multiple higher cortical functions, including memory, thinking, orientation, comprehension, calculation, learning capacity, language, and judgment. Consciousness is not clouded. Impairments of cognitive function are commonly accompanied, and occasionally preceded, by deterioration in emotional control, social behaviour, or motivation. This syndrome occurs in Alzheimer’s disease, in cerebrovascular disease, and in other conditions primarily or secondarily affecting the brain.

In assessing the presence or absence of a dementia, special care should be taken to avoid false‑positive identification: motivational or emotional factors, particularly depression, in addition to motor slowness and general physical frailty, rather than loss of intellectual capacity, may account for failure to perform.”

127.  Insofar as it is material to the issue at hand, I should also refer to the following diagnostic guidelines in the ICD‑10:

“The primary requirement for diagnosis is evidence of a decline in both memory and thinking which is sufficient to impair personal activities of daily living, as described above ... The above symptoms and impairments should have been evident for at least 6 months for a confident clinical diagnosis of dementia to be made.” (emphasis added)

128.  One of the matters explored in Prof Lieh Mak’s oral evidence was the requirement for a confident clinical diagnosis of dementia to be made that the relevant symptoms and impairments should have been evident for at least six months.  Prof Lieh Mak’s suggestion under re‑examination on Day 50 (28 August 2015) that the “6‑month” criterion could be ignored or “presumed”in a retrospective assessment[22] is without basis and unsupported by authorities.

Fluctuation of Cognition[23]

129.  The significance of the fluctuating nature of DLB is that, as explained by Dr Förstl (with whom Dr Chiu agreed), “individual snapshots” at a given time would not be representative of a longer period; in order to ascertain the competence or incompetence of a DLB patient such as Mr Leiduck, one would need to actually look at his performance on that particular day at that particular time; thus it would be wrong to generalise and each session has to be examined individually.

130.  Whilst there is consensus between the experts that DLB patients experience fluctuations and that the periodicity of the fluctuations range from minutes, hours, days or weeks and varies from patient to patient and even for the same patient,[24] Prof Lieh Mak on the one hand and Dr Förstl and Prof Chiu on the other disagreed on the following aspects of the feature of fluctuation.

What fluctuates?

131.  The first aspect of the controversy is what actually fluctuates in DLB.

(1)  On one hand, Prof Lieh Mak initially took the position that only attention and alertness fluctuates, other cognitive functions (like comprehension, complex attention, learning, complex motor function and complex executive function) do not fluctuate.  Then, on day 43 (26 May 2015), while accepting under cross‑examination that cognition and cognitive performance do fluctuate, Prof Lieh Mak suggested that their fluctuation is “subject to” or “contingent upon” fluctuating alertness and attention.  Prof Lieh Mak’s final position under further cross‑examination on day 44 (27 May 2015) was that other domains do fluctuate independent of attention and alertness but that such fluctuation would be minor.

(2)  On the other hand, according to Prof Chiu, whilst attention and alertness do fluctuate prominently, other domains of cognitive functions also fluctuate. Although the diagnosis of dementia would not fluctuate (which is in the first place based on abnormalities in cognitive function and functioning over a prolonged period) and the brain pathology leading to dementia would not fluctuate, the clinical manifestation of dementia in DLB, including attention, cognitive function and functioning of the patient, fluctuates markedly.  Disturbance in attention is not the sole explanation for fluctuating cognition.  While there is association between fluctuating cognition and attention disturbances, the fluctuating cognition in DLB is not 100% contingent upon disturbances in attention and alertness.

(3)  Dr Förstl agreed with Prof Chiu that it is not just attention and alertness that fluctuate, but that the “performance/behaviour” of the patient fluctuates.  Such fluctuations in performance and behaviour (“memory, planning, language, recognition, executive and other intellectual functions”) occur “because his alertness and attention go up and down, because nerotransmitter systems ... are less balanced, because the underlying Lewy‑body ... have already affected a large number of neurons within these systems.  All of this makes the patient more vulnerable to distress, physical or psychological, intrinsic or extrinsic”.

132.  I prefer the views of Dr Förstl and Prof Chiu to that of Prof Lieh Mak for the following reasons.

133.  First, the fluctuation that is described as a core feature in both the Consensus Criteria and DSM‑5 is “fluctuating cognition with pronounced variations in attention and alertness” (emphasis added).

134.  Second, the preponderance of research and medical literature produced in these proceedings alludes to fluctuations in cognition and cognitive performance, and not just in attention and alertness, and does not suggest that fluctuating attention and alertness is the sole reason for fluctuating cognition.  The following examples, in chronological order, have been identified by Mr Wong SC:

(1)  McKeith et al, “Operational criteria for senile dementia of Lewy‑body type” (“McKeith 1992”):

“fluctuating cognitive impairment” (p 912 left)

“The most striking features of the [DLB] was their widely fluctuating performance on all measures — cognitive, mental state, physical, and behavioural...” (p 913 right)

“Fluctuating memory impairment was characteristic of the [DLB] patients with delirious features...” (p 913 right)

Fluctuation in “[h]igher cortical functions” is observed (p 915 left) 

“The fluctuating cognitive performance with periods of relative lucidity and intact memory function” (p 917 right‑p 918)

“The extent to which [DLB] patients fluctuated in their cognitive performance requires repeated emphasis” (p 918 left)

“A more sustained cognitive impairment had become established albeit with market fluctuations in severity” (p 919 left)

“The presence of fluctuating cognitive impairment is essential and must be of a degree sufficient to cause variations either in functional ability or performanceon repeated tests of cognitive function” (p 921 left top)

(2)  McKeith, “Dementia with Lewy bodies” (“McKeith 2004”):

“The core clinical features of DLB ... are fluctuating cognitive impairment ...” (p 335 left, Table II [B25(2)/40/315])

“Fluctuations in cognitive functions, which may vary over minutes, hours, or days, occur in 50% to 75% of patients, and are associated with shifting levels of attention and alertness...”

(p 336 left)

(3)  D Neef et al, “Dementia with Lewy Bodies: An Amerging Disease” (“Neef 2006”):

“Fluctuating cognition is characteristic of [DLB]; these fluctuations may occur over minutes, hours, or days” (p 1226 left text box)

(4)  Bradshaw et al, “Higher cortical deficits influence attentional processing in dementia with Lewy bodies, relative to patients with dementia of the Alzheimer’s type and controls” (“Bradshaw 2006”)explains the mechanism in a more detailed fashion:

“The findings from this study also make a potentially important contribution to our understanding of the neurocognitive underpinnings of fluctuations in DLB. Fluctuation is indeed a multidimensional phenomenon, characterised by fluctuation not only in attention but also in behaviour, functional abilities and cognitive function more generally. ...On another level, by showing that there may be a cortical contribution to attentional processing in DLB, our findings raise the possibility that the gross, clinically observable fluctuation in behaviour and functional ability may be cognitively modulated, depending on situational factors and the degree to which demands are being placed on impaired cortical function.” (p 1134)

(5)  McKeith, “Dementia with Lewy bodies” (“McKeith 2007”):

“Fluctuations in cognitive function, which may vary over minutes, hours or days, occur in 50–75% of patients and are associated with shifting levels of attention and alertness... Cognitive fluctuations may contribute to large variability in repeated test scores. eg 5 MMSE points difference over the course of a few days or weeks” (p 532 right § 60.2.2)

“The most common errors among less experienced clinicians were failure to recognize cognitive fluctuations unique to DLB patients ...” (p 533 left § 60.3.1)

(6)  Rongve & Aarsland, “Dementia with Lewy bodies and Parkinson’s disease dementia”[25] (“Rongve & Aarsland 2013”):

“...core symptoms, i.e. well‑formed visual hallucinations and cognitive fluctuations” (p 469 left)

“Cognition Fluctuating” (p 473 table 35.2)

“Cognitive Fluctuations

Fluctuations in DLB commonly occur in both cognition and level of arousal and sleepiness ...” (p 473 right)

(7) Taylor et al, “Covariant perfusion pattern provide clues to the origin of cognitive fluctuations and attentional dysfunction in Dementia with Lewy bodies” (“Taylor 2013”):

“A core symptom of DLB is that of fluctuating cognition (FC), which can affect up to 90% of patients (McKeith et al., 2005).  Clinically, these spontaneous alterations in arousal, attention, and cognition can have significant impacts on patient function (Ballard et al., 2001)”

(8) Donaghy & McKeith, “The clinical characteristics of dementia with Lewy bodies and a consideration of prodromal diagnosis” (“Donaghy & McKeith 2014”) which described the fluctuations in DLB as “fluctuating cognition” and later on “fluctuating attention and cognition”; and

(9) Donaghy et al, “Prodromal dementia with Lewy bodies” (“Donaghy 2014”) which also described the fluctuation as “fluctuating cognition” only (at pp 422 and 427).

135.  The papers produced or referred to by Prof Lieh Mak do not actually support her view in any of its successive forms.

(1)  Prof Lieh Mak referred to the following statement in the chapter on DLB by Prof McKeith (“McKeith 2012”) in the New Oxford Textbook of Psychiatry, 2^nd Edition, Volume 1, page 361:

“Fluctuation in cognitive performance and functional abilities, which is based in variations in attention and level of consciousness, is the most characteristic feature of DLB and the one which causes greatest diagnostic difficulties.”

(2)  Prof Lieh Mak seized upon the wordings in McKeith 2012to say that by 2012, Prof McKeith had changed his opinion from his previous papers and opined that fluctuation was “based in” therefore contingent upon variations in attention and level of consciousness.

(3)  The suggestion that the opinion of Prof McKeith or other acknowledged experts in the field has changed such that they now take the view that fluctuations in DLB are either limited to fluctuations in attention, or that the fluctuations in cognition are solely the result of disturbances in attention does not stand up to scrutiny.  One just has to look at Rongve & Aarsland 2013, Donaghy & McKeith 2014 and Donaghy 2014 cited in para 134 (6), (8) and (9) above.

(4)  Prof Lieh Mak also referred a two‑page introduction of DLB in the website of the National Institute of Neurological Disorders and Stroke which described the central features of DLB toinclude “progressive cognitive decline, “fluctuations” in alertness and attention, visual hallucinations, and parkinsonian motor symptoms, ...”.  This is not a research article or medical study, but is an article (author unknown) on a website that seeks to promote, in a general (and brief) way, awareness of DLB to the general public.  I think I can be excused for not according it the same weight as the other serious medical paper intended for use by researchers, academics and medical professionals. 

Can a patient fluctuate back to normal or near normal cognitive functioning?

136.  There is little dispute that the amplitude of fluctuations in DLB is “marked” or “substantial”.

137.  Both Dr Förstl and Prof Chiu opine that a DLB patient can, in the course of these fluctuations, return to normal or near normal level performance during the good moments of their fluctuations, especially in the early stages of the dementia.

138.  Prof Chiu explained normal or near normal performance to mean:

(1)  “the cognitive functions appear relatively well, similar to normal, but they still suffer from dementia as a diagnosis...  Because of their cognitive functions, so good that it is similar to normal level”;

(2)  “Near normal means it is comparable to normal, but it may not be — because for cognitive testing it depends on what you are testing... you don’t score 100 percent in every aspect”.

139.  Of course, as confirmed by Prof Chiu, normalcy means what is “normal for that person”, and that “one person’s normal cognitive ability would be different from the normal cognitive ability of another person”.

140.  Dr Förstl and Prof Chiu’s understanding is consistent with the preponderance of authorities.  Mr Wong SC highlighted these:

(1)  McKeith et al, “Consensus guidelines for the clinical and pathological diagnosis of dementia with Lewy bodies” (i.e. the 1^st report of the consortium on DLB) (“McKeith 1996”):

“In the earliest stages, patients may show deficits of cognitive function and global performance that alternate with periods of normal or near‑normal performance.

...

The other extreme of fluctuation ... are periods of apparent spontaneous remission during which recall of recent information is evident and other cognitive functions may briefly return.” (p 1115 right)

(2) Ferman, “Dementia with Lewy Bodies: A Review of Clinical Diagnosis, Neuropathology And Management Options” (“Ferman 2000”):

“The fluctuations in DLB are described as variations in cognition or arousal that may range from lucid interaction to reduced clarity of awareness and clouded consciousness. Fluctuating arousal may reflect periods of unresponsiveness while awake (e.g., blanking out, zoning out), episodes of excessive somnolence despite adequate night time sleep, or periods of daytime behavioural confusion with limited awareness of surroundings alternating with normal or near normal function. Cognitive fluctuations have also been described as variability in the patient’s cognitive or functional abilities and periods when the patient regains his or her ability to perform tasks that he or she was previously unable to carry out.”

(3) Ferman et al, “DLB fluctuations: Specific features that reliably differentiate DLB from AD and normal aging” (“Ferman 2004”):

“Fluctuating cognition have been described as periods of behavioural confusion, inattention, and incoherent speech alternating with episodes of lucidity and capable task performance.” (p 181 left)

(Prof Chiu postulated that “capable task performance” implies the regaining of function.)

(4) Bradshaw et al, “Fluctuating cognition in dementia with Lewy bodies and Alzheimer’s disease is qualitatively distinct” (“Bradshaw 2004”) which described their findings of fluctuation in these terms:

“Verbatim qualitative descriptions of FC in DLB suggested an interruption in the flow of awareness or attention. This was frequently associated with transient episodes of confusion and an inability to engage in meaningful cognitive activity, followed by reversion to a near normal level of function. These episodes occurred spontaneously, in the absence of a situational explanation, suggesting that they were internally driven. By contrast, fluctuations in AD reflected a diminished capacity to cope with the cognitive demands of the immediate environment.” (p 386 left)

And which set out in Table 4 (p 386) the following real life examples given by caregivers about the good and bad moments of a DLB patient:

“Worst: He was hallucinating, his character changed and he got loud, almost aggressive.

Best: He was only slightly muddled.

Worst: She required full direction with ADLs, was lethargic, dribbling and confused to time, place and routine.

Best: She was alert, aware of her routine and familiar with the other residents.

Worst: He couldn’t work out how to charge his electric razor or plug it in.

Best: He attended to clerical work and paid the bills.

Worst: She was nonsensical, confused, and mumbled incoherently.

Best: She was almost as she was.

Worst: She got up at 2:30 am and got dressed for an appointment.

Best: Periods where she seems to think quite clearly, made sense and remembered things.

Worst: He woke in the morning and thought there was a drama somewhere and he had to be there, I couldn’t convince him otherwise.

Best: He woke up calm, and was more easily convinced not to worry.

Worst: He kept looking for “the exit”, couldn’t find the bedroom or the bathroom and had trouble recognising me (wife).

Best: He was alert, opened the door, and greeted me after work. He knew me and seemed pleased to see me.

Worst: She was seeing people, preparing extra meals, and asking how many people to cook for.

Best: Normal conversation, made sense, nothing unusual.

Worst: Illogical discussion, all jumbled, and didn’t make sense.

Best: Made himself clearly understood.”

(5)  Neef 2006:

“Physicians should not rely on clinical impressions at a single visit, because the patient’s cognitive impairment may range from near normal to severe confusion.” (p 1226 left)

(6)  Rongve & Aarsland 2013:

“Fluctuations in DLB commonly occur in both cognition and level or arousal and sleepiness, with some patients changing rapidly from normal alertness and cognition within seconds or minutes, yet others have much slower shifts of days or weeks.” (p 473 right)

(7)  Y Huang & G Halliday, “Can we clinically diagnose dementia with Lewy bodies yet?” (“Huang & Holiday 2013”) [B27/26/199] which quoted the above passage from Ferman 2000 with agreement (p 3);

(8)  Taylor 2013:

“Remission to near‑normal cognitive function can occur spontaneously in the absence of clear environmental triggers” (p 1917)

(Prof Chiu read “remission” as a stronger word than “fluctuation” and as strongly suggesting the return or recovery to normal performance.)

141.  The following authorities according to which a DLB patient could achieve scores in the MMSE test within the normal range commonly ascribed to a non‑demented person also indicate a capability to return to normal cognitive ability:[26]

(1)  McKeith 1992 [B25/38/302]

“Of SDLT patients 40% scored 29 or more out of 37 on the MTS, a level above that commonly accepted (26/37) for identifying demented cases... At presentation therefore, 40% of the SDLT patients were scoring above the MTS threshold for dementia.” (p 913 left)[27]

(2)  Consensus Criteria:

“Composite global cognitive assessment tools such as the Mini‑Mental State Examination (MMSE) cannot be relied upon to distinguish DLB from other common dementia syndromes and some patients who meet the criteria for DLB will score in the normal range.”

142.  The marked fluctuations that DLB patients experience are such that Dr Förstl would explain to a patient who has just been diagnosed with DLB in the following terms:

“Look, Mr Meyer, do not be surprised, I have to explain your letter or medical report will say that you suffer from dementia with Lewy bodies. Now, we all know you are not demented today at 10 o’clock in the morning and you will not be demented hopefully for the next weeks and months, you have an increased risk of developing more serious problems. We can prevent that because you will respond much better to an anti‑dementia drug compared to the average patient with so‑called Alzheimer’s dementia, so we should consider giving you that anti‑dementia substance fairly soon right now. We see no reason for doing that, but should these problems come back, speak with your doctor and he should prescribe that. On the other hand, you’ve been badly confused over the last nights, and if that happens again you should not accept a prescription of haloperidol and other neuroleptics because it may be detrimental for you.”

143.  Dr Förstl also said in para 5.2.f of his 2^nd report:

“... a person bouncing back to normalcy after a diagnosis of for example a dementia with Lewy bodies, would temporarily not satisfy the criteria for a dementia and therefore the diagnosis of dementia with Lewy bodies would have to be discarded until he again became demented.”

144.  What I understand Dr Förstl to be saying here is that a DLB patient can bounce back to such a level of cognitive functioning that he can effectively be said to be not demented.

145.  In contrast, according to Prof Lieh Mak, there can never be fluctuation back to normal once a patient is diagnosed with DLB.  She initially put forward two bases to explain this:

(1)  Once a function is lost, it is irretrievable due to the simple fact that once brain cells die, they are dead and there can be no generation of new cells or new connections.

(2)  Dementia is characterized by an irreversible and a “linear downhill course of decline” (which Prof Lieh Mak demonstrated by drawing a straight downhill line with her hand).

146.  The first basis was offered without authority and was abandoned by Prof Lieh Mak after much cross‑examination on day 46 (29 May 2015).

147.  With regard to the second basis, on day 44 (27 May 2015), again after much cross‑examination, Prof Lieh Mak accepted that the course is one which is “fluctuating downwards” (and gave a corresponding hand demonstration).

148.  Nevertheless, in so conceding, Prof Lieh Mak maintained that fluctuation could never be back to the “baseline”, i.e. “the level of cognitive performance achieved by the patient before he became demented”.  That is to say, the patient would not, even during a good “swing”, be able to achieve the level of cognitive performance attained by him before he became demented. 

149.  To explain this, Prof Lieh Mak suggested for the first time in cross‑examination that DLB is essentially “dementia superimposed by delirium”; that DLB “fluctuation is a delirium, but not a fluctuation of the underlying dementia” and that delirium would not give the patient normal performance.  Under cross‑examination, Prof Lieh Mak backed down and revised the description of DLB to “symptoms of delirium imposed upon dementia”.

150.  I have great difficulty in following Prof Lieh Mak’s analysis.  Her contention that there could be no fluctuation back to normalcy or near normalcy is against the weight of the authorities set out in para 140 above.  The equation of the fluctuations experienced by DLB patients to delirium or delirious symptoms goes against common sense.  Fluctuations would by definition be between good and bad and between up and down. Prof Lieh Mak’s theory leaves the “good” and the “up” unexplained.

151.  To sum up, I am unable to accept Prof Lieh Mak’s evidence. I find that DLB progresses in a fluctuating downhill course and that the fluctuations are of marked amplitude with the patient being capable of putting up normal or near normal performance in the good/up “swings”.  While the period of normalcy would get less and less as the DLB progresses, I accept Prof Chiu’s evidence that normal or near normal performance is still possible during the moderate stage though there will be a point when the DLB has progressed to such severity that even a good swing would not be able to push performance of the patient back to normalcy.

Other differences

152.  There was also a debate as to which part of the brain deteriorates and which function is lost first.  To put this in context, Prof Lieh Mak initially suggested that DLB develops “Top‑Down” in that the higher functions would be affected first before basic functions are impaired.  From this she argued that if a DLB patient has suffered impairment to his basic functions already, then his higher cortical functions must necessarily have already been severely impaired.  On this basis, Prof Lieh Mak relied on the level of basic personal care that Mr Leiduck required as evidence of the severity of his cognitive impairment.

153.  Although much time has been spent in both evidence and submissions on this, it is unnecessary for me to resolve this issue for the simple reason that I am not persuaded that, having regard to the whole picture before me, it is more probable than not that Mr Leiduck’s dependence on others for basic personal care and the various other matters in 2008, 2009 and 2010 relied upon the plaintiff were symptoms of a dementia, whether DLB or VaD.

154.  Another topic canvassed in cross‑examination and submissions is BPSD which refers to a cluster of symptoms including delusions, hallucinations, agitation/aggression, depression/dysphoria, anxiety, elation/euphoria, apathy/indifference, disinhibition, irritability/ lability, aberrant motor behaviour, sleep and appetite and eating disorders.[28]  The main aspects explored are the cause of BPSD (whether they are multi‑factorial) and whether BPSD have a direct correlation with the severity of the dementia or cognitive impairment so that the behaviourial symptoms of Mr Leiduck that one can observe from the records kept on him by his first nursing home in Essen during the period from February 2012 to April 2013 can be used to gauge his cognitive performance and hence competence.

155.  Again, on proper analysis of all the evidence available, I need not deal with this issue, interesting those it is.  This is so because even if the defendants are right that BPSD are multi‑factorial in cause and that they do not have a direct correlation with the severity of the dementia or cognitive impairment, it is my view that the defendants have failed to discharge the burden of proof on them that it is more probable than not that Mr Leiduck had bounced back to a level of cognitive functioning that made him competent as a witness when he signed his (2^nd) 5^th affidavit, 6^th affidavit, witness statement, supplemental witness statement and answers to interrogatories on 27 September 2011, 11 January 2012, 19 September 2012, 15 November 2012 and 28 January 2013 respectively.

156.  All three experts were asked about how they would stage Mr Leiduck’s dementia at different times.[29]  Given that we are concerned with Mr Leiduck’s competence on specific dates and that cognitive fluctuations occur at all stages of DLB and VaD, I do not derive any real assistance from a general statement that Mr Leiduck’s DLB and VaD had approximately reached what stage at what time.

157.  On these notes, I turn to the question whether Mr Leiduck suffered from DLB or VaD in 2008, 2009 and 2010 even before Dr Gallard’s diagnosis.

Available Information about Mr Leiduck’s Health

158.  Mr Leiduck was born on 9 January 1930.  So he was 78 years old at the beginning of the material period of time.

159.  Mr Leiduck was throughout the period with which we are concerned suffering from a number of physical illnesses and ailments, some of a chronic nature with increasing severity (especially heart diseases). 

160.  The earliest record available to us that documented Mr Leiduck’s heart conditions is a medical report dated 23 November 2001 relating to his hospitalisation from 5 to 23 November 2001.  This was followed by repeated hospital admissions in subsequent years.  The heart conditions deteriorated over the years, necessitating a surgery for recanalization for left‑dominant coronary circulation in November 2001, further surgery for recanalization of the RIVA in January 2003 and eventually the implantation of a pacemaker in February 2008. Indeed, the substantial body of medical records we see in this case were generated by the hospital admissions for treatment of Mr Leiduck’s various physical illnesses and ailments.

161.  Mr Leiduck also suffered from a condition called retinitis pigmentosa, which is a progressive disease having these features:

(1)  The age of onset is usually adolescent or early adulthood.

(2)  The early symptom is night blindness.  Vision deteriorates gradually and the person is usually legally blind by mid‑adult life.  The end stage is complete blindness.

162.  The medical report dated 23 November 2001 already noted that Mr Leiduck had significant visual impairment due to bilateral retinitis pigmentosa.  A medical report dated 27 March 2008 in relation to his hospitalisation from 5 to 30 March 2008 recorded the fact that Mr Leiduck had 100% disability and required a care level of 1 due to his amaurosis.  Upon his admission to hospital again on 24 May 2008, he was documented in the nursing record as having just 1% sight. Mr Leiduck became completely blind sometime in 2011 or 2012.

163.  As a result of his heart and other physical conditions, Mr Leiduck had been repeatedly admitted into hospitals in every year since 2001 (i.e. the year from which we have Mr Leiduck’s medical records).  Mr Wong SC counted at least 26 admissions, 10 of which were between 2008 and 2010, as set out in Appendix 2 to his written submissions dated 6 May 2016.

164.  Of particular relevance to us is that during these hospital admissions, Mr Leiduck also underwent 7 neurological examinations, 2 psychological examinations and 2 psychiatric assessments as follows:

(1)  clinical neurological examination during 15 to 16 October 2004 which “did not show a neurological deficit”;

(2)  psychological examination during 11 to 17 November 2006 with findings that Mr Leiduck was “alert, oriented, conscious”;

(3)  neurological examination during 7 to 11 October 2007 which did not reveal any abnormalities;

(4)  neurological examination during 17 February to 5 March 2008 in which no focal neurological deficits were found;

(5)  exploratory neurological and psychological examinations during 5 to 30 March 2008 with “normal” findings;

(6)  neurological and psychiatric consultations (arising from recurrent panic attacks due to known coronary heart disease and hyperliproteinaemia) on 26 May 2008 with these findings: “conscious, alert, oriented”; “organised line of thoughts” and “cooperative, responses adequate”;

(7)  psychiatric consultation on 27 May 2008 in the course of which the following was noted:

“Feels panic mostly at night, describes in detail that this is triggered by perceived changes in heartbeat (presumes this, but doesn’t actually detect anything)

Also waking up due to panic (patient describing panic; appears only to be uneasiness), is afraid of escalating.

Patient panics, vicious circle [illegible] in heart makes panic worse)

...

Treatment – discussion on the causes; looked for ways to deal with panic; not productive at this time. Patient presumably cannot cope with panic.”

(8)  general neurological examination during 17 to 22 February 2010 yielding “normal” findings.

165.  There was no record of any diagnosis, findings, complaints or even suggestion of any cognitive impairment prior to July 2011.  Dr Förstl (who is of course familiar with the environment where Mr Leiduck was treated) made the following observation on Day 38 (14 April 2014):

“I felt that the environment where [Mr Leiduck] was treated was a very modern and effective environment. They would not have neglected a significant case of dementia.”

166.  It was during the 4 to 18 July 2011 admission that Mr Leiduck was referred to Dr Gallard for a neurological examination on 7 July 2011. 

167.  The report by Dr Gallard following his examination of Mr Leiduck on 7 July 2011 read as follows:

“History:

According to the medical history given by a third party (wife) there have been a number of occurrences in which the patient has experienced visual hallucinations, some scenic. On the day he was admitted as an inpatient, his wife found him disoriented in the early hours of the morning in the living room, having turned on all the lights and saying everything was ‘full of Russians’. She later discovered him on the floor in a pool of urine, legs bent, wrapped in a blanket, claiming there was a canal running on either side of him. Later on he lay down in bed with his head at the foot of the bed and said that the Chinese were there.

He has had noticeable movement disorder for a long time; his wife has put this, along with the occasional falls, down to his poor vision. In the meantime there have been times where it takes him several seconds to react to speech. After a stay in hospital in Werden he was discharged with the medication Risperdal, which she then discontinued after consultation with the patient’s GP as it caused tiredness and confusion.

He sometimes confuses events and facts and at times falls to recognize his current situation. He can also sometimes be verbally aggressive.

Until the start of the year he had been drinking at least two ales or a bottle of red wine each evening and had done so for years, which she has since reduced significantly.

Findings:

Possibilities of neuropsychological testing is significantly limited due to bilateral amaurosis (can now only see shadows). At present the patient is oriented to person, place and time (only stated his age incorrectly).

Perception is good, concentration not significantly affected. Memory appears to be age‑appropriate. Rambling formal thought processes, currently no disorder of thought content.

Affect is generally friendly, at times is somewhat irritable (repeatedly cuts examinations short), sufficiently able to express changes in emotion. Has retained impulses. Delayed motor functions. The patient ascribes his ‘malfunctions’ to his loss of vision.

Neurologically, the patient experiences hypokinesia and akinesia with difficulty starting movement and also takes very small, cautious steps due to poor vision, no significant rigidity, no tremor, no paresis or high grade sensory disturbances. Hypophonic, slightly unmodulated speech with no aphasia. Occasionally irregular nystagmus mainly to the left. No ocular muscle paresis.

Assessment and recommendations:

In summary, Lewy body dementia must be taken into account when considering the combination of fluctuating vigilance and cognition disorders with relatively good memory performance on the one hand, and repeated visual scenic hallucinations and extrapyramidal symptoms on the other, as well as repeated falls (although these have mostly not been observed by others) (CCT and EEG inconclusive).  Because a common symptom of this disease is increased hallucinations from L‑Dopa, rivastigmine therapy is recommended, e.g. in patch form, 4.6 mg/d and increased to 9.2 mg/d in 4 weeks at the earliest.  Attention: use classical neuroleptics (Incl. risperidone) and anticholinergic drugs with caution.”

Any unsoundness of mind before Dr Gallard’s diagnosis?

168.  Against the aforesaid background, the plaintiff surmised that Mr Leiduck’s dementia had been overlooked by the doctors who treated him before July 2011. In support, the following points were made:

(1)  DLB is not a common form of dementia.[30]

(2)  Diagnosing DLB is inherently difficult, especially for clinicians who are not involved in treating dementia on a daily basis.[31]  It would also take more than a single visit to ascertain because of the great amplitude in fluctuations, in some visits the patient may appear normal or near normal in their cognitive function, but in the next visit they can have severe confusion.

(3)  A diagnosis of dementia is to a significant extent dependent on accurate information and details provided by an informant who knows the patient well.  Mr Leiduck’s family members (particularly his wife who had been stated as having the tendency to overestimate Mr Leiduck’s abilities) may not have drawn his symptoms to the attention of his treating doctors.

(4)  Mr Leiduck’s doctors were focusing on his other more acute illnesses.  For example, in 2008 when Mr Leiduck was admitted into hospital for panic attacks which are not associated with dementia, his assessment would be focused on the immediate issue (i.e. panic attacks) and there would be no cogent reason to specifically assess the presence of dementia or other cognitive impairment.

(5)  Doctors would not confront Mr Leiduck and raise the issue of dementia until there were obvious and relatively advanced symptoms exhibited.

(6)  The cognitive examinations conducted on Mr Leiduck might not have been of the appropriate or requisite nature, extent and depth that would reveal cognitive impairment.

(7)  Mr Leiduck had an impressive façade, especially in the better moments of his illness, so that one may not be able to immediately detect cognitive impairment on a conversational level.

169.  With respect, if there is evidence that Mr Leiduck had started to suffer from DLB or VaD in 2008, 2009 and 2010, these reasons may explain why the dementia was not diagnosed until July 2011.  However, they do not, without more, establish or even tend to establish Mr Leiduck’s allegedly undetected dementia.  So the real question is whether Mr Leiduck did or did not exhibit any symptoms of DLB or VaD in 2008, 2009 and 2010.

2008

170.  For the year 2008, I wish to start by taking on board Mr Wong SC’s observations that Prof Lieh Mak’s opinion that Mr Leiduck had started to suffer from DLB and was thereby incompetent in 2008 was initially supported on 6 bases and that only 2 of these grounds have been retained by the plaintiff in final submissions.  Like Mr Wong SC, I cannot help but wonder where this leaves the plaintiff given that Prof Lieh Mak expressly did not rely on any of the original 6 bases as being conclusive but as painting the “whole picture”.

171.  Be that as it may, the plaintiff still pointed to the following:

(1)   a CT scan conducted in October 2004 indicating multi‑infarct syndrome with a pronounced subcortical arteriosclerotic encephalopathy and resulted in a diagnosis of multi‑infarct syndrome;

(2)   the nursing care history taken by the Elisabeth Hospital in Essen on 24 May 2008 showing that Mr Leiduck required assistance in basic personal care, such as washing, dressing, shaving, etc and the following entries in the nursing records kept in respect of Mr Leiduck:

24.5.2008

“Patient requires help in all day‑to‑day activities.”

25.5.2008

“Help with basic care”

“Patient did not sleep entire night, more restless than in the day.

“Patient disoriented at times.”

26.5.2008

“Patient confused cannot find way to room.”

“Patient urinated in dayroom, not following instructions to call night‑duty staff.”

“Patient walked out of room again into corridor, he got lost, was brought back to his room and was asked to ring if he needs anything or needs to be taken to the WC.”

27.5.2008

“Patient confused again — was on ward and couldn’t find his way to room. Was aggressive when he was led back to his room. Felt patronised and misunderstood.”

172.  I shall deal with these in turn.

CT scan

173.  There is a distinction between pathology and symptoms, and the two do not correlate.[32]  All the experts agreed that one cannot make diagnosis of dementia from brain pathology — dementia is a syndrome and not a disease, and can only be diagnosed from clinical symptoms, not CT scan results which are not part of the diagnostic criteria.  Most infracts (more than 80%) observed in CT scans are actually silent infracts that have no clinical manifestation at all.

174.  As explained by Dr Förstl, whilst a person with such brain changes may have a statistically increased risk of developing dementia in the future, this is just one of the many factors that might contribute to a later manifestation of dementia, but “it would not allow me to make an individual prediction that this person will probably become demented within the next five years.”

175.  Prof Lieh Mak admitted that “there’s no correlation between the extent of damage and the functional loss”; that “it's not possible to say that [Mr Leiduck] was demented or the degree of dementia” and that she was just “making the assumption that it is possible to have some degree” of dementia or cognitive impairment (the basis of which Prof Lieh Mak did not make clear).  In the end, she accepted that without memory loss, the CT scan would not warrant any diagnosis of dementia.

Need for help with basic care

176.  First, the nursing care history actually recorded both Mr Leiduck’s need for personal assistance and that he was not suffering from dementia.  Mr Leiduck was also noted in the same document as being alert, orientated (to identity, situation, location and time), active, cooperative and even‑tempered and as having clear speech. 

177.  Second, as explained by Prof Chiu and Dr Förstl, referring to DSM‑5,in order to diagnose dementia, it must first be shown that there is cognitive decline that interferes with independence in everyday activities, i.e. the loss of independence in everyday activities is due to the cognitive deficit, because there can be any number of reasons for a person’s loss of independence in everyday activities that have nothing to do with cognitive deficit.  One cannot reverse the logic and use the need for personal assistance to diagnose dementia.

178.  In Mr Leiduck’s case, common sense would suggest that he required personal care assistance because of his advanced aged, poor physical health and visual impairment.

Behaviour in ward

179.  I agree with Mr Wong SC that the entries extracted in para 170(3) above should be read in context:

(1)  that Mr Leiduck was in pain and was feeling very unwell (thoracic oppressions, outbreaks of sweating, dyspnoea);

(2)  that he was blind[33] and found himself in an unfamiliar environment;

(3)  that delirium (or “confusional state”)[34] is a very common phenomenon in hospitals, particularly for elderly patients and Mr Leiduck's physical conditions (pain, visual impairment and chronic heart diseases including coronary heart disease, ventricular extrasystoles and reduced left ventricular function) are well‑known risk‑factors for delirium and made him predisposed to develop delirium; and

(4)  that Mr Leiduck had been prescribed with not less than 4 types of medications which were delirium‑inducing: Tavor (lorazepam) (which would have the side‑effect of producing pradoxical increase in aggression); Zopiclone (which was prescribed in maximum dosage); Aponal (doxepin); and Atosil (promethazine).

180.  I have no difficulty in accepting Mr Wong’s submission that the entries in the nursing records of the May 2008 Admission at most suggest a minor and transient confusional state suffered by Mr Leiduck at night, and caused by a “whole package” (using Prof Chiu’s expression) of factors including Mr Leiduck’s physical conditions, blindness and the drugs that he was receiving during the time.

181.  This is soundly reinforced by:

(1)  the findings of the neurological and psychiatric consultations underwent by Mr Leiduck on 26 and 27 May 2008 (see paras 163(6) and (7) above).  I can see no evidence, other than Prof Lieh Mak’s unsupported assertion, that suggest that the two specialists who saw Mr Leiduck had missed out on his dementia; and

(2)  the fact that Mr Leiduck had completely recovered from the delirium and that the nursing record showed that he was normal when he was discharged on 28 May 2008.

182.  Most importantly, there was no other report of any mental condition — delirium or otherwise - in the whole of 2008 at all.

2009

183.  For 2009, the plaintiff referred to the following as demonstrative of dementia:

(1)  these entries in the nursing records kept by the Elisabeth Hospital in Essen in respect of Mr Leiduck’s stay over 7 days from 15 to 21 October 2009:

15.10.2009

“Telephone number of wife not given”

16.10.2009

“Patient showered by nursing staff.”

“neuro consultation requested”

“Patient spontaneously not able to control bowel movements, some released into trousers”

19.10.2009

“Patient complained in the evening that he hadn’t received his beer.”

“Chat with patient, aggressive, indignant, demanding beer (despite being told several times that this is not possible), claims consultant prescribed it”

(2)  the increase since May 2009 in Mr Leiduck’s nursing care level from Level 1 to Level 2 (meaning a need for continuous skilled nursing care and meaningful availability of restorative services in addition to minimum basis care and services — at least 3 hours per day, 2 hours of which is basic care) and the notation in the Medicproof Expert Assessment dated 16 May 2012 (“2012 Medicproof Report”) that according to a preliminary assessment dated 29 June 2009 (“2009 Assessment”), “since the preliminary assessment, the insured patient’s condition has worsened further, including in terms of cognitive ability”.

Wife’s telephone number

184.  Prof Lieh Mak speculated that the phone number was not given because Mr Leiduck had forgotten his wife’s phone number due to his dementia.

185.  The entry in the nursing records was very brief, apart from recording that the telephone number of the wife was not given, no further details was provided.  The fact that Mrs Leiduck’s telephone number was not given could be due to any number of reasons.  It was pure speculation on Prof Lieh‑Mak’s part to assume that Mr Leiduck had forgotten about the phone number.

186.  Even if the telephone number did slip Mr Leiduck’s mind, it is in any event not that uncommon to find people forgetting phone numbers, including phone numbers of oneself and one's spouse.  One such incident is not something from which dementia could be inferred. 

187.  It should also be perfectly understandable in light of the circumstances under which Mr Leiduck was admitted and the symptoms that he was exhibiting at that time.  Mr Leiduck was rushed to the hospital by ambulance, with angina pectoris, shortness of breath, cold sweats, headache, dizziness, palpitations with a new onset of atrial fibrillation, which is a very serious life-threatening condition(Mr Leiduck was put on heparin treatment because the doctors considered him as having a high risk of stroke).  Mr Leiduck could well be so unwell physically that he was not able to respond to a request for phone number.

Bowel movement

188.  This is a non‑point.  Prof Lieh Mak conceded after much cross‑examination that Mr Leiduck did not have faecal incontinence and this entry could simply be because Mr Leiduck felt pain, which was common for elderly patient, and the release was an accident.

Aggression

189.  The plaintiff attempted to classify this as BPSD.  However, as pointed out by Prof Chiu, this kind of behaviour could be seen in a lot of normal elderly who are not demented.  One cannot put the cart before the horse.  One has to diagnose dementia first before one moves on to judge whether certain repeated behaviour — aggression, anger, depression, fear etc — is BPSD.  One cannot turn around the logic and diagnose a person to be demented because he was found indignant or aggressive on a particular occasion, when his request for something he wanted was denied.

190.  As in 2008, there was no other report of any mental condition or behaviourial issue in the whole of 2009 at all.

Nursing care level

191.  The assessment of nursing care level was merely an assessment to ascertain the amount of time for personal care assistance in terms of hours and minutes that a person requires.

192.  Insofar as Mr Leiduck was concerned, the MediClin Report dated 27 March 2008 recorded that “due to [Mr Leiduck’s] amaurosis he has a Degree of Disability of 100 and a care level of 1”.

193.  The report of the 2009 Assessment is not available but the 2012 Medicproof Report noted the following about the 2009 Assessment:

“There is a nursing care need for care level 2 since May 2009

The patient’s everyday competence is not (significantly) impaired

Fully inpatient care is not recommended”

194.  Prof Lieh Mak relied on these records to argue that the increase in the level of Mr Leiduck’s need for nursing care could not be explained by his physical conditions but must have been the result of the view taken by the Medicproof experts that Mr Leiduck was suffering from dementia in 2009.

195.  This argument, however, ignored what was recorded under the heading “Previous history relevant to nursing care” in the 2012 Medicproof Report:

“Heart failure due to multiple myocardial infarctions, pacemaker implanted in 2009. Retinitis pigmentosa of the eyes with blindness (monthly disability benefit for the blind) for many years. Balance disorders. Until the patient went into a care home, he was looked after at home by his wife; however he was admitted to a care home because he kept falling, he would slip over in his urine. He did not tell his wife when he needed to pass bowel movement or pass water. From 5 to 16 April 2012 he was admitted as an inpatient due to a urinary tract infection with exsiccosis and bronchitis. During this stay he was also diagnosed with dementia (Lewy body dementia) with delusional disorder and adjustment of medication. Difficult relationship between wife and nursing staff as the wife believed the insured patient could still do a lot himself.”

196.  It is clear that, contrary to Prof Lieh Mak's conjecture, the nursing care level was recommended by reason of the various physical illnesses (such as heart failure, blindness, balance disorders, etc.) in 2009.

197.  As far as the Midicproof experts were concerned, dementia only became relevant for the assessment of nursing care level since April 2012.  If indeed dementia had been diagnosed or its possibility detected and considered relevant in 2009, it would have been mentioned in the medical history, as the Medicproof experts in May 2012 clearly had the repot of the 2009 Assessment in their hands for reference.

198.  Even in 2012, according to para 3 of the 2012 Medicproof Report, the diagnoses relevant to Mr Leiduck’s need for nursing care were:

“3.1 Diagnoses justifying nursing care

Complete blindness due to retinitis pigmentosa

Heart failure, scoliosis of the spine.

3.2 Diagnoses (§4 para. 16 and 17 MB/PPV 2010)

Cognitive disorder based on the onset of reduced brain capacity with misperceptions, overestimation of patient’s ability, and stool and urine incontinence.”

199.  That is to say, even in 2012 (after DLB had already been diagnosed and fully taken into account), the Medicproof experts did not consider Mr Leiduck’s DLB to be a “diagnosis justifying nursing care” in assessing the nursing care required by him.  It is hence most unlikely that 3 years earlier when the Medicproof experts made the 2009 Assessment, they were making it on the basis that Mr Leiduck was suffering from dementia — but somehow made no reference whatsoever to it (or else the “previous history” in the 2012 Report would have referred to it).

2010

200.  For 2000, the plaintiff relied on the following notations in the record relating to Mr Leiduck’s hospitalisation from 5 to 8 July 2010:“need for assistance with personal care”; “need for constant supervision” and “delirium, not further identified”.

201.  I believe these have already been dealt with in the above paras 175 to 177 (need for help with personal care) and paras 178(3) and 179 (delirium) where I dealt with similar issues regarding the May 2008 hospitalisation.

202.  As in 2008 and 2009, there was no other report of any mental condition or behaviourial issue in the whole of 2010 at all.

203.  To take stock, there were only three documented confusional states or suspected confusional states, all of which occurred during hospitalisation and from which Mr Leiduck apparently recovered fully, in the entire 3 years from 2008 to 2010.  They came nowhere near fulfilling the relevant diagnostic criteria, to which one should always go back.

204.  Indeed, it appears to me that the plaintiff (relying on Prof Lieh Mak’s assessment) was making a mountain out of a molehill.

205.  The plaintiff’s case relating to 2008‑2010 is fully met by the following answers given by Dr Förstl to Mr Wong SC’s questions on day 60 (24 February 2016):

Q: So these three occasions are all we’ve managed to find.  But in between, we are talking about a time span from 2008 to July 2011, a period of more than three years, with three occasions in the record, all of which related to hospitalization, all of which occurred circumstances which you say a confusional state would not be surprising even for normal, elderly person.

A: Yes.

Q: So you would not be able to draw from such evidence to say that such confusional states are indicative of any dementia?

A: Certainly not of a dementia, but of an increase of developing dementia in due course, ‘due course’ meaning the whole observation period that is available.

...

Q: Do you mean a risk?

A: Yes, a risk.

Q: A risk of developing dementia in some future years?

A: Yes.

Q: But as to when that may come?

A: Certainly not.

Q: You won’t be able to say?

A: No.

Q: It may never come, actually?

A: Indeed.

206.  In light of the evidence, the only conclusion that I can draw regarding 2008, 2009 and 2010 is that Mr Leiduck had not started to suffer from either DLB or VaD, and was therefore not of unsound mind, in those years.

207.  What I can however accept is that the behaviour that led to the consultation with and examination by Dr Gallard probably occurred more than once for a while before that visit.  That much is clear from the “History” section of Dr Gallard’s report (para 166 above). However, I consider it unnecessary to dwell on this, seeing that Mr Leiduck did not produce any written evidence after 6 April 2010 and before 27 September 2011.

208.  For the avoidance of doubt, in coming to the aforesaid conclusion in respect of 2008‑2010, I did not apply any “presumption of competence”.  In my view, such a “presumption” merely describes the implicit basis upon which the court receives evidence from a witness whose competence is not in issue.  It has no place when competence is contested.  When there is a challenge, competence has to be proved on the evidence without reference to any presumption.  In such a situation, where there is no evidence of incompetence and the court rules in favour of competence (as in this case), the court is taking a view on the evidence and is not applying any “presumption of competence”.

Capable of receiving just impressions of fact and or of relating them truly on 27.9.2011, 11.1.2012, 19.9.2012, 11.5.2012 and 28.1.2013?

209.  Mr Leiduck moved into a nursing home in Essen on 2 February 2012 and stayed there until 18 April 2013.  Included in the papers were 161 pages of care records kept by this nursing home which detailed Mr Leiduck’s condition and behaviour and changes therein, good or bad, on a daily basis.

210.  In making the defendants’ case that the DLB (or VaD) did not produce the relevant incapabilities under section 3(b) after July 2011, Mr Wong SC referred to and relied on what these care records said about Mr Leiduck on the dates with which we are concerned as well as those immediately before and after them:

(1)  19 September 2012 (date of the witness statement):

Date/Time	Remarks
18/09/2012
9:45 am	Resident Mr Herbert Leiduck was asked about his wishes for meals as well as possible.  Praise and criticism were accepted.
9:50 am	I asked the resident whether he would like to listen to reading out loud; he was very interested, but said that he wanted to wait because he has important appointments today.  But definitely next time.  He was very nice and happy about this information.
1:17 pm	Mr Herbert Leiduck rang at 12:15 pm.  He was standing n the bathroom naked and wanted to shower.  I explained to him that this was not a good time since it was lunch time.  Mr Herbert Leiduck became very loud in response.  Discussion with Mr Gorkowski, which also brought nothing. Consequently Mr Herbert Leiduck was showered during lunch.
Afternoon	Conversations to maintain contact
19/09/2012
Afternoon	Conversations to maintain contact
20/09/2012
1:31 pm	Mr Herbert Leiduck was happy about fried potatoes, eggs sunny side up and iceberg salad — a lunch which was made by some residents in the home group and tasted wonderful.

(2)  15 November 2012 (date of the supplemental witness statement):

Date/Time	Remarks
14/11/2012
Morning	Mr Herbert Leiduck would like to have a shower in the afternoon.
3:29 pm	Ms Leiduck told me that her husband will be receiving a visit from his attorney, Dr Albert Hagerney, tomorrow 3pm.  We should let him see her husband.  She left Mr Leiduck’s personal ID here; it is in the personal ID box.
6:45 pm	Mr Herbert Leiduck wanted to go have a shower, but chose the wrong door.  He was standing n the hallway naked.  I helped him back to his room and into the bath.
15/11/2012	No record
16/11/2012
Morning	Mr Herbert Leiduck would like to have a shower in the afternoon.
9:30 am	Conversation to maintain contact.  Mr Herbert Leiduck is obviously feeling well.  The resident enjoyed telling stories.

(3)  28 January 2013 (date of the answers to interrogatories):

Date/Time	Remarks
27/01/2013
8:35 pm	Mr Herbert Leiduck asked me whether there would be mixed bathrooms now, why I would let women into his bathroom. Once, he took of his clothes in the room during the day, he spread the clothes across the room on the floor and was griping, he waited for over two hours, he said he peed in his pants. When I answered that I only just started my shift he called me bad names, I would be a liar.
8:45 pm	Supplement: In the meantime, he was friendlier again and even said thank you for things done to or for him.
28/01/2013
4:31 am	Mr Herbert Leiduck wanted to fly to China so that he could continue his work there.  Mr Herbert Leiduck told me that he had worked a lot today and had gotten tired, therefore he is indulging himself with a couple bottles of beer.
10:00 am	Resident Mr Herbert Leiduck was informed that fresh potato pancakes will be served today.  The resident was very happy.
Evening	Mr Herbert Leiduck wanted to have potato pancakes with apple sauce again like at lunch.
6:32 pm	Mr Herbert Leiduck rang to call me in the afternoon and immediately griped at me, why I could put the coffee “in front of his nose” without telling him anything about it — apparently he couldn’t remember it — it supposedly had gotten cold now because of my fault, I should bring him a hot coffee immediately.  I brewed it again and brought it to him.
29/01/2013	No record

211.  I have considered these care records very carefully.  While they do show that Mr Leiduck was not in one of his bad days on 19 September 2012, 15 November 2012 and 28 January 2013 (with some qualification for the last‑mentioned date since he did exhibit some BPSD in the small hours and in the evening), they do not on proper reading actually show that those were necessarily good days.  The only notation for 19 September 2011 was that there were conversations between Mr Leiduck and his carer to maintain contact.  There was no entry in respect of 15 November 2012 at all.

212.  And for 27 September 2011 (i.e. the date of the (2^nd) 5^th affidavit) and 11 January 2012 (i.e. the date of the 6^th affidavit) which were before Mr Leiduck’s move to the nursing home, the only matter that Mr Wong SC could draw my attention to was that Mr Leiduck was not in hospital on those dates.

213.  In any event, it is not sufficient for the defendants who bear the burden of proving that Mr Leiduck was not incompetent within the meaning of section 3(b) to just show that Mr Leiduck was not in a bad “swing” on the subject dates.  Accepting that a DLB patient can fluctuate back to normal or near normal cognitive performance, what is required is some evidence that Mr Leiduck did in fact fluctuate back to such a level of performance that he did not appear incapable as defined in section 3(b).

214.  Submissions such as that Mr Leiduck was probably still in an early (or even prodromal) stage of the dementia and that long good moments tend to be more abundant at such a stage do not help in fixing Mr Leiduck’s actual mental condition on the particular dates on which he produced written evidence.

215.  The same goes for the positive observations on Mr Leiduck’s general mental state before the death of his wife provided by the informants interviewed by Dr Förstl, given the fluctuations in cognition and the unpredictability of such fluctuations in terms of periodicity and amplitude.  These informants obviously did not see Mr Leiduck on a daily basis or on any of the subject dates.

216.  Nor can I derive assistance from the contents of the written evidence itself (which Mr Wong SC described as “logical, consistent, coherent and filled with relevant details”).  I have not been told how they were prepared, in particular, whether Mr Leiduck drafted them himself or whether he just gave instructions to his lawyers who then turned his instructions into the affidavits and witness statements in question and, if so, the quality of such instructions.

217.  Lastly, Mr Wong SC reminded me of the fact that Mr Leiduck signed some of the documents in Germany before a notary public who certified that the contents of the documents had been read to Mr Leiduck who understood and approved them.  Of relevance for present purposes are the notary certificates by one Dr Martin Alberts:

(1)  the one dated 19 September 2012 in respect of Mr Leiduck’s witness statement;

(2)  the one dated 15 November 2012 in respect of Mr Leiduck’s supplemental witness statement; and

(3)  the one dated 28 January 2013 in respect of Mr Leiduck’s answers to interrogatories.

218.  These certificates did not actually describe Mr Leiduck’s mental state as observed by the notary public.  In any event, it is not clear if the notary public was qualified to assess Mr Leiduck’s competence or if he did so assess Mr Leiduck at all.  On this, I believe I am entitled to draw on my own personal experience of observing Mr Leiduck give evidence under cross-examination in sessions of 2 hours or so on 15 days from 25 February to 7 June 2013 and having no inkling whatsoever that he was in fact incompetent except on 8 May 2013.  It was not until Mr Leiduck returned in August 2013 that I began to detect that something might be wrong.

219.  On the evidence, I am driven to the conclusion that the defendants have not discharged the burden of proving that Mr Leiduck was not incompetent on 27 September 2011, 11 November 2011, 19 September 2012, 15 November 2012 and 28 January 2013.  It follows that the written evidence signed by Mr Leiduck on those dates are inadmissible on the ground of incompetence of the witness.

220.  In this connection, I do not agree with Mr Wong SC’s construction and understanding of the competency issue directions.  According to counsel, under those directions:

(1)  The inquiry was not one to be conducted by the parties filing evidence of their own.

(2)  It was to be conducted by Dr Förstl as the single joint expert who should then report to the court.

(3)  The parties were just to provide to Dr Förstl only such evidence, documents and information that were requested by him.

(4)  It was therefore up to Dr Förstl to decide what he needed in order to answer the competency issue.

(5)  That being the case, there was no reason for the defendants to think that they were entitled or required to adduce further factual evidence not asked for by Dr Förstl.

221.  I have great difficulty with Mr Wong SC’s position.  I have reviewed the transcript of the hearing at which the competency issue directions were argued.  It was never suggested that the usual adversarial nature of the proceedings before this court should be changed; that this court should abdicate any of its duties to the single joint expert; or that the usual principles governing the incidence of the burden of proof should be disapplied.  Paragraphs 6 and 7 of the Order dated 15 November 2013 (under which the single joint expert should provide the parties with a list of all the documents etc. he would require for the preparation of his report and the parties were to comply with such list) were included in the interest of saving the time and costs that might otherwise be wasted by a general discovery exercise without the expert’s input.  They were not intended to restrict and did not have effect in restricting either party’s right to adduce evidence not sought by the single joint expert.  It was up to either party to decide what further evidence (if any) they should lead upon hearing from Dr Förstl in 2014 that the materials that had been provided to him were sufficient for him to conclude whether Mr Leiduck was competent or incompetent when making his affidavits and witness statements.

222.  Lastly, while I disagree with Prof Chiu’s conclusion of competence, I am mindful that Prof Chiu reached such view largely on the understanding that there is a presumption of competence.  Prof Chiu is not to be criticised.  Whether such a presumption exists or operates is a matter of law.  I repeat what I have said in para 207 above.

Summary of findings

223.  In summary:

(1)  The defendants have discharged the burden of proving that Mr Leiduck was not of unsound mind and therefore not incompetent in 2008 to 2010.

(2)  Mr Leiduck’s 1^st, 2^nd, 3^rd, 4^th and (1^st) 5^th affidavits are admissible.

(3)  The defendants have not discharged the burden of proving that Mr Leiduck was not incompetent on 27 September 2011, 11 November 2011, 19 September 2012, 15 November 2012 and 28 January 2013. 

(4)  Mr Leiduck’s (2^nd) 5^th affidavit, 6^th affidavit, witness statement, supplemental witness statement and answers to interrogatories are inadmissible.

224.  I am grateful to counsel for both parties for their assistance.

225.  I shall hear the parties on the effects of the findings made in this judgment and on costs on 7‑9 December 2016.