CHAU YUEN HEUNG v. JEKCO ELEVATORS LTD

HCPI 956/2015

[2021] HKCFI 1095

IN THE HIGH COURT OF THE

HONG KONG SPECIAL ADMINISTRATIVE REGION

COURT OF FIRST INSTANCE

PERSONAL INJURIES ACTION NO 956 OF 2015

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DECISION

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I. INTRODUCTION

1.  The plaintiff (“P”) was an employee of an estate agency who worked on the 18^th floor of Fook Yip Building, 53-57 Kwai Fung Crescent, Kwai Chung, New Territories (“Building”). The defendant (“D”) was the maintenance contractor of the 8 lifts at the Building (collectively, “Lifts”).

2.  It was P’s case that at/about 9:35pm on 9 November 2012 she took Lift No 4 (“Lift”) at the 18^th floor of the Building to go to the ground floor. When the Lift descended to about the 10^th floor, it suddenly accelerated in an over-speed and uncontrolled manner until it hit the lift shaft structures at/about the 28^th (top) floor and then came to a stop. P claimed the sudden impact caused the metal ceiling of the Lift to fall off, and her neck, shoulders, back and right foot were struck by unknown objects (“Accident”). P was subsequently rescued from the Lift.

3.  On 10 November 2017, D and the Electrical and Mechanical Services Department (“EMSD”) carried out visual check of the overall Lift system, and found (a) the counterweight buffer was hit by the counterweight (“CWT”) and all suspension ropes were slackened due to overshoot of the Lift, (b) the broken shaft of the traction machine (“Traction Shaft”) was found near the position of the traction sheave as viewed from the gearbox opening, (c) the traction sheave was found in an inclined position, and (d) 2 bolts detached from the traction machine were found in the machine room.[1]

4.  The broken Traction Shaft with associated gearbox were sent to EMSD headquarters. Pursuant to EMSD’s request, D arranged for a third party surveyor Victory Harmony Limited (“Victory”) to conduct a weight test to measure the total weight of the lift equipment acting on the traction sheave. The total weight of the lift car (“LC”), CWT, hoisting ropes and compensation chain of the Lift was found to be 4,325kgs with tolerance ±10kgs.[2]

5.  Further examination was done on 3 December 2012 by an independent expert. As recorded in EMSD’s Final Investigation Report dated 21 May 2013 (“FIR”) prepared by E&M engineer Mr Ng Tak-hei (“Mr Ng”) of EMSD’s General Legislation Division, according to measurement of the exposed section of the Traction Shaft and examination of the fracture surface, the following were inter alia observed: (a) circular machining marks, (b) crack propagation on the solid core of the shaft, and (c) clear signs of heat damage around the outer ring of the shaft.[3]

6.  According to D (as recorded in paragraph 4.4 of FIR):

7.  Mr Ng opined in FIR as follows:

8.  On 8 September 2015 P commenced the main action against D for negligence and/or for breach of the common duty of care by D, its agents and/or servants, and on 12 June 2017 P filed her Amended Statement of Claim (“ASoC”). D accepted that an accident happened on 9 November 2012 when the Lift carrying P as passenger (who intended to go from the 18^th floor to the ground floor of the Building) ascended until it stopped upon impact at the top of the lift shaft, but D disputed liability by filing its Amended Defence on 5 July 2017 (“ADefence”).

9.  On 28 September 2017, D filed a Third Party Notice (“TPN”) against 1^st TP and all owners of the Building (“2^nd TP”) (collectively, “TPs”). According to the order of Master Roy Yu dated 9 November 2017, the TPN stood as D’s statement of claim in the third party proceedings. TPs also admitted that P met with an accident on 9 November 2012 when she took the Lift, but they disputed liability by filing their Amended Defence and Counterclaim (“AD&C”) on 27 August 2019. On 5 September 2019 D filed its Amended Reply to the AD&C (“AReply”), and on 10 October 2019 TPs filed their Amended Rejoinder to the AReply (“ARejoinder”).

10.  According to the 4^th affirmation of D’s solicitor Tang Chi Keung (“Tang”) filed by D on 7 October 2020 to support the D/TPs Expert Summons referred to in paragraph 37 below (“Tang 4^th Aff”), a core issue in dispute in the third party proceedings was whether there had been major alterations to the Lift that increased the overall load/weight of LC and CWT, which 1^st/2^nd TPs failed to inform EMSD / D prior to 2008[4] and which compromised the Lift’s Traction Shaft.

11.  By the order of Master Roy Yu dated 9 November 2017, (a) TPs were granted liberty to appear and to take part at the trial of the main action as the trial judge shall direct and they shall be bound by the result of such trial, and (b) subject to direction by the trial judge, the question of TPs’ liability for contribution or indemnify to D be tried after the trial of the main action.

12.  On 14 March 2018 P filed a summons for leave to join TPs as the 2^nd/3^rd defendants in the main action, but on 17 April 2018 Master Roy Yu granted leave for P to withdraw such summons.

13.  The present action had been set down for trial. The pre-trial review was scheduled to be heard on 10 December 2021, and the trial was scheduled to commence on 9 March 2022 with 8 days reserved.

II.     FACTUAL WITNESSES

14.  The factual witnesses at trial would be (a) P (who had given 2 witness statements dated 21 November 2016 and 29 April 2017), (b) D’s director and general manager Mr Chan Tak Wah (who had given 2 witness statements dated 12 January 2017 and 7 March 2019, “Mr Chan”), (c) D’s director Mr Keung Yuk Hon (who gave a witness statement dated 2 May 2017, “Mr Keung”),[5] and (d) 1^st TP’s property manager Mr Yeung Yiu Kei (who gave a witness statement dated 12 March 2019, “Mr Yeung”).

15.  According to Mr Yeung’s witness statement dated 12 March 2019 (“Yeung Witness Statement”),

“6. [The Building]的8部升降機[ie Lifts]約於1986年左右由[Chevalier]負責安裝，並於1987年左右開始運作。於1987年6月至1997年7月期間，[Chevalier]為[the Building]的升降機[ie Lifts](包括[the Lift])的保養承辦商，並負責提供檢查/保養/維修服務。於1997年7月至2007年12月31日期間，由[Holake]接管升降機的檢查/保養/維修服務工作。由2008年1月1日起，由[D]負責升降機的檢查/保養/維修服務工作，直至2013年11月29日。上述幾間升降機公司均以全保形式為[the Building]提供升降機的檢查/保養/維修服務工作。

7. 據本人所了解，[Holake]曾於2006年7-8月期間為[the Lift]進行更換控制組件工程，包括更換電腦控制系統、變壓變頻VVVF升降機驅動器、控制櫃、升降機箱內及升降機大堂㩒手板及顯示屏、升降機控制纜及遙遠監察系統。當中沒有進行任何更換牙箱主軸、主軸燒焊或改裝主軸等工程。於完成上述工程後，[Holake]於2006年9月7日簽署當時[EMSD]指定的表格7。

8. 另外，據本人所了解，因[the Lift]主要的用途是客運，所以為著其美觀裝飾的關係，[the Lift]的內部牆身是裝上玻璃鏡及雲石地台，但因事隔太久，[1^st TP]及[2^nd TP]並沒有存留相關紀錄。無論如何，當升降機承辦商投標前及中標後，它們理應了解[the Building]的8部升降機[ie Lifts]曾經作出的翻新工程。況且，根據保養合約的條款，升降機承辦商要為[the Building]的8部升降機[ie Lifts]作定期保養及檢查，及定期試驗安全設備/年檢，包括安全設備滿載試驗及超載感應系統試驗等。” (my emphasis)

16.  Mr Yeung’s statement dated 16 January 2013 to EMSD with annexures (“Yeung EMSD Statement”) were attached as appendix 1 to the Yeung Witness Statement dated 12 March 2019. In the former statement, Mr Yeung stated as follows:

“問7: 記錄有沒有顯示[Lift] 有沒有作出更新工程, 如裝修等?

答7:    有文件記錄的有由[Holake] 於1997年更換[the Lift] 地下外門及內門同時更換地膠及旁板。另外, [D] 未有大型更新工程, 而[Chevalier] 由於新安裝未有為[the Lift]做任何更新工程。”

III.   EXPERT REPORTS ON LIABILITY

17.  On 16 May 2016, Master Leong granted leave for P and D to adduce expert evidence on liability from Ir Lo Kok Keung (“Ir Lo”) for P and Professor C K Cheung (“Prof Cheung”) for D. On 28 January 2019, Master Roy Yu granted leave for D to replace Prof Cheung with Professor Andrew YT Leung (“Prof Leung”).

18.  On 28 January 2019, Master Roy Yu directed P and D to cause Ir Lo and Prof Leung to address the following issues in their expert reports on liability:

By such order, Master Roy Yu also granted directions for exchange of solo provisional expert reports on liability to be followed by a without prejudice meeting between Ir Lo and Prof Leung both of whom would then compile a joint report.

19.  By the same order, Master Roy Yu granted leave for D and TPs to adduce expert evidence on liability from Prof Leung for D and Ir Kong Sin Ming (“Ir Kong”) for TPs, and for such experts to address on the issues in paragraph 18(a)-(b) above. Directions were also granted for exchange of solo provisional expert reports on liability to be followed by a without prejudice meeting between Prof Leung and Ir Kong both of whom would then compile a joint report.

20.  For the main action, on 1 and 5 March 2019 Ir Lo and Prof Leung compiled their respective provisional expert report (“Lo Report” and “Leung 1^st Report”), and on 19 March 2019 Ir Lo and Prof Leung compiled their joint expert report (“Lo/Leung Jt Report”).

21.  For preparation of the Leung 1^st Report, a copy of the Yeung EMSD Statement was given to Prof Leung. The Leung 1^st Report stated as follows:

“Section 6. Possible Scenario of the Incident

9. It was said in Section 6.1 of the FIR that ‘The broken of the traction machine was the cause of the lift cage to be ascending over-speed unintentionally until hitting the structural ceiling’. I agree with that because [CWT] was heavier than [LC] plus a passenger so that [LC] ascended due to gravity of [CWT].

10. It was said in Section 6.2 of the FIR that ‘The fatigue crack was originated from the outer edge of the shaft that had been trimmed from 100mm to 90mm. The cause of the fatigue crack was due to the stress concentration effect from the damage induced when the original shaft was machined away to create the room for insertion of sleeve’.

11. Fracture has two main stages: crack initiation and propagation. While it is correct to say that stress concentration initiates the crack, stress concentration is not necessarily created by machine damage, it can be created by improper design. In this case, it is the L-shaped radius made by the vertical surface of the 155mm diameter and the horizontal surface of the 90mm diameter after trimming, i.e., the radius at the meeting point of the vertical and horizontal surfaces. Stress concentration occurs when the radius is small. In that case stress concentration can also be created by perfect machining. If Section 6.2 of the FIR were correct, crack could be initiated any place along the machine trimmed shaft and not necessary where it actually fractured.

12. Another important stage is propagation that is determined by an S-N curve. S is the stress level suffered and N is the frequency of S occurrences. There is an S level that will never trigger propagation that is called the endurance limit, below which most mechanical design adhere to. When S exceeds the endurance limit, it is a matter of time that fracture will occur. From his email on 20 December 2012, [Mr Ng] indicated that there was an increase of the load of the counterweight of lift no 8.

13. There is also a photograph, photo 1, showing 10 new bricks added to the old bricks at 50 kg a brick. The increase was 500 kg before the engagement of [D] as the maintenance contractor. The increase in [CWT] should also increase the weight of [LC], that is 380kg for optimal balance. The total increase is 880kg. It was reported in Section 4.6 of the FIR that the total weight of [LC], [CWT], hoisting ropes and compensation chain of [the Lift] was found to be 4,325kg ± 10kg. After deducting the weights of hoisting ropes and compensation chain as calculated by Alex Ng of [D] on 11 December 2012, the weight of [LC] is 1,648kg and [CWT] 2,170kg, totalling 3,818kg. The total original weight should be 3818 – 880 = 2938kg. Therefore, the total increase of load that the shaft was suffering was 880 / 2938 = 30% which is substantial to move S away from the endurance limit. I conclude that the propagation leading to fracture over the years was due to S exceeding the endurance limit by the increased load.”

22.  In the Lo/Leung Jt Report, both Ir Lo and Prof Leung agreed with section 6.1 of FIR, and Prof Leung reiterated his observation in paragraph 9 of the Leung 1^st Report (see paragraph 21 above).

23.  In the Lo/Leung Jt Report, on section 6.2 of FIR, Prof Leung repeated his views in paragraphs 11-13 of the Leung 1^st Report (see paragraph 21 above), and Ir Lo opined as follows:

“3(6). I agree EMSD’s findings in Section 6.2 of FIR. If no welding work on the sleeve ends welded to the main shaft (traction shaft), there would be no high temperature to affect the strength of steel property and main shaft would not break during long period of operation. But after sleeve replacement with two times of welding work on both ends of the sleeve welded to the main shaft respectively on October 2011 and November 2011, the main shaft was broken after a short period (12 months) of operation. It was evident that the strength of the steel was weakened due to the welding work. The welding heating temperature (over 1000ºC) which would damage the property of the steel, consequently weaken the strength of main shaft, resulting in a risk of failure of the main shaft. It was obviously the worker adopted inappropriate repair work method. In practice, one should adopt interference fit by heating the sleeve until inner diameter expand to reach the tolerance limit and put on the main shaft completely inserted into the sleeve and allow the sleeve to cool down by natural.”

24.  In respect of section 5.3 of FIR that stated “[a] sleeve was then inserted, figure 3. The sleeve was machine into a step like feature with a chamfer (sic) so that its larger outer diameter was 115mm, smaller outer diameter was 100mm and its inner diameter was 90mm. The two ends of the sleeve were then welded to the original shaft, and this sleeve served as the seat for bearing”, Prof Leung opined as follows:

“(1) Welding is meant to strengthen a component; (2) If welding were the main cause of fracture, it should have broken at the 90mm diameter welding position rather than the 115mm position which was 25mm away from the failure point; (3) From Ref 1 that the temperature distribution at distance:

0mm 2500^oC

7mm 900^oC

19mm 400^oC

28mm 250^oC

Therefore, at distance 25mm from weld point in this case, it had practically no effect at all.

The root cause of failure was the additional load of 880kg to the shaft rather than temperature.” (my emphasis)

25.  For the third party proceedings, on 6 and 3 May 2019 Prof Leung and Ir Kong compiled their respective provisional expert report (“Leung 2^nd Report” and “Kong Report”). On 14 June 2019, Prof Leung and Ir Kong respectively gave written comments on each other’s provisional expert report (“Leung Comments” and “Kong Comments”). On 19 August 2019, Prof Leung and Ir Kong compiled their joint expert report (“Leung/Kong Jt Report”).

26.  For preparation of the Leung 2^nd Report, a copy of the Yeung EMSD Statement was given to Prof Leung. In the Leung 2^nd Report, Prof Leung reiterated his views in paragraphs 9-13 in the Leung 1^st Report. In the Leung/Kong Jt Report, it was stated as follows:

“6. How did the material alterations to [the Lift] in or about 2006 relate to the metal fatigue found in [FIR] of EMSD.

6.1 Kong opined that the material alterations to [the Lift] in or about 2006 had no relation to the metal fatigue found in the FIR of EMSD according to the report of [Holake] on 13/7/2006.

6.2 Leung opined otherwise as [Mr Ng] of EMSD noted the weight increase of Lift 8 in an email of 20/12/2012 and the EMSD informed [1^st TP] in a letter dated 2/1/2013 that the EMSD noted Lift 8 which had the same design and model as [the Lift] had increased counterweight which might have compromised the integrity of the traction shaft. [1^st TP] was asked by the EMSD on 18/1/2013 to confirm if [CWT] of Lift 8 has also been increased. In the Supplemental Witness Statement of [Mr Chan], the material alteration to [the Lift] in or about 2006 should have included the increase of [CWT]. The total increase of 880kg was quite substantial to trigger the metal fatigue found in the FIR.

6.3 Kong disagreed the above statement 6.2. The letter from EMSD to [1^st TP] did not state any material alteration to [the Lift]. The said material alteration as suggested by [Mr Chan] in his Supplemental Witness Statement including the increase of dead weight of [CWT] and [LC] decoration have not been included in the Contract of modernisation among Holake and IO. Moreover, the total increase of nearly 1000kg in statement 6.2 should be further proved.

6.4 Further, as shown in the Ground Floor Plan in respect of the project of ‘Proposed Factory Building and Extension of Cold Storage Building at K.C.T.L. 341 Kwai Chung N.T.’ (now known as [the Building]) (‘the Plan’) recently obtained from the Building Department and provided by the parties, both [the Lift] and Lift No.8 were built as passenger lifts (For parties’ reference, ‘P. Lift 4’ mean ‘Passenger Lift 4’ and ‘Lift For D P’ mean ‘Lift For Disable And Passenger’ as mentioned in the Plan).

7. Other issues not mentioned in FIR that the experts have some disagreements

7.1 The welding temperature damage on the metallic material that was resolved at the expert meeting as not important.

7.2 The influence of the addition of nearly 500kg decoration weight and 500kg [CWT] on [the Lift] remains an issue to check with manufacturer if the original design had such allowance.”

IV.     PROCEDURAL HISTORY

27.  According to the Tang 4^th Aff, Tang claimed he/D did not know that major alterations had been done to the Lift prior to 2006. Mr Chan’s 2^nd witness statement dated 7 March 2019 stated that on 15 March 2010 D discovered addition of 10 counterweight bricks for the Lift (paragraph 14), and that during investigation of the Accident on 9 November 2012 EMSD’s Mr Ng in the presence of D’s Mr Keung/ Mr Chan and 1^st TP’s Mr Hugo Leung Man Lok and Mr Yeung also counted an increase of 10 counterweight bricks said to weigh about 500kgs for each of the Lift and also Lift No 8 of the Building (“Lift 8”).

28.  Tang also noted the Yeung Witness Statement stated the Lift was mainly a passenger lift and for cosmetic reasons glass mirrors had been installed on its interior walls plus marble flooring, but due to lapse of time TPs had not kept any related records of such renovation works (paragraph 8) (see paragraph 15 above).

29.  The Tang 4^th Aff claimed that since D had limited knowledge of major alterations to the Lift, and there were lack of records to show by whom, when and how major alterations were done, D filed a summons on 17 July 2019 to require TPs to verify their List of Documents filed on 21 September 2018. On 29 July 2019, Master Roy Yu directed TPs to so verify their List of Documents by affidavit and to file/serve supplemental list of documents (also to be verified by affidavit) to disclose newly acquired documents within 28 days. On 21 August 2019, TPs filed Mr Yeung’s 3^rd affirmation to verify TPs’ List of Documents filed on 21 September 2018 and their Supplemental List of Documents filed on 21 August 2019.

30.  The Yeung EMSD Statement with annexures as attached to the Yeung Witness Statement had as its annexure 6 a table titled “福業大廈升降機主要維修記錄”[8] concerning 18 items of maintenance done to the Lifts from April 1995 to May 2019 (“Table”). At the last column of the Table corresponding to those 18 items were various references from “P1” to “P27”. Whilst other columns of the Table described the nature of information set out in those columns, eg date, maintenance item, contractor and fees, there was no such description for the last column of the Table. According to the Tang 4^th Aff, D after some time and as a result of meticulous examination of the Table discovered these references, which D suspected might be references to 27 pages of documents (“27 Pages”).

31.  So on 17 January 2020, D’s solicitors (“DSols”) wrote to TPs’ solicitors (“TPSols”) to request for copy of the 27 Pages. On 5 February 2020, TPs provided the copy 27 Pages to D. Tang claimed pages 2-5 of the copy 27 Pages gave details of renovation/upgrading works done to the Lift in/about September 1997, which showed Holake as maintenance contractor carried out the works set out in paragraph 83(a)(i)-(v) below. Further, page 7 of the copy 27 Pages showed that in/about May 2002 the plastic floor tiles of the Lift were replaced, and paragraph 8 of the Yeung Witness Statement confirmed they had been replaced with marble tiles.

32.  The Tang 4^th Aff noted the Leung 2^nd Report explained the development of fatigue fracture had 2 main stages, ie crack initiation and propagation (paragraph 11), and propagation is determined by the S-N curve whereby S is the stress level suffered and N is the frequency of S occurrences (paragraph 12) (see paragraph 21 above). Prof Leung further explained the S level that will never trigger propagation is the endurance limit below which most mechanical designs adhere to, but when the S level exceeds the endurance limit it will be a matter of time for the fatigue fracture to occur. In paragraphs 6.2, 6.3 and 7.2 of the Leung/Kong Jt Report (see paragraph 26 above), the experts opined on how material alterations to the Lift related to metal fatigue as found in FIR. In essence, Prof Leung opined that material alterations to the Lift increased its total weight by 880kgs, which increase was quite substantial to trigger metal fatigue as found in FIR, but Ir Kong was of the view that the suggested total increase of nearly 1,000kgs should be further proved.

33.  On 21 February 2020, D first raised with P/TPs the issue of obtaining supplemental joint expert reports on liability, but there was no reply. On 17 April 2020, D informed P/TPs it had provided the 27 Pages to the Department of Justice (“DoJ”) on behalf of EMSD. On 13 May 2020, DoJ replied to confirm that Mr Ng had not seen the 27 Pages when he prepared FIR. On 22 May 2020, D sent DoJ’s reply to P/TPs.

34.  On 29 May 2020, as a result of TPs’ disclosure of the 27 Pages, D raised interrogatories to obtain further information from 1^st TP. On 3 July 2020, 1^st TP filed/served its Answer thereto by way of Mr Yeung’s affirmation (“Answer”) which, in short, revealed that Mr Yeung was responsible for compiling the 27 Pages but such documents had not been submitted to EMSD:

35.  On 7 July 2020, DSols and TPSols attended a hearing before this court in relation to a matter arising from the third party proceedings, and at such hearing this court raised some issues concerning the future conduct of the present action. On 31 July 2020, DSols wrote to inform P’s solicitors (“PSols”) about the issues raised by this court, and to propose a temporary stay of the main action pending final determination of the third party proceedings. On 24 August 2020, PSols indicated agreement to such proposal.

36.  TPs claimed that upon careful consideration they disagreed with D’s proposal to temporarily stay the main action and to first proceed with the third party proceedings. Instead, TPs proposed that the main action and the third party proceedings be tried together so that the issues of liability between P and D and between D and TPs be adjudged by the court at the same time. TPs acknowledged it was unlikely P would be found liable for contributory negligence, but noted P still carried the burden to prove her case against D in order to hold D liable for the injuries she suffered, and TPs’ consequent liability to D for contribution/ indemnity (if any) would depend on inter alia D’s liability/culpability to P, ie if P failed to establish liability against D, then no issue of contribution/ indemnity by TPs would arise. TPs were concerned that if the third party proceedings were heard and/or resolved before the main action, then even though D disputed liability vis-à-vis P, determination of D’s claim in the third party proceedings would not determine the issue of liability between P and D (ie whether D was negligent and/or caused / contributed to the Accident) which would remain alive until determination by the court in the main action. TPs therefore considered it would save time and costs for both the main action and the third party proceedings to be tried together so that the issue of liability between P and D and the issue of contribution/indemnity between D and TPs could be duly determined by the court in one go.

37.  Given TPs’ stance, DSols in further correspondence with TPSols requested TPs to consent to D’s proposed amendments to the TPN and to cause Prof Leung / Ir Kong to prepare a supplemental joint expert report. When TPSols did not respond, D filed a summons on 14 September 2020 (“Amend TPN Summons”) for leave to amend the TPN in the manner marked in red as per the draft annexed thereto (“Draft ATPN”) with proposal for directions concerning consequential amendments to other pleadings in the third party proceedings. On 7 October 2020 and upon counsel’s advice, D filed a summons (“D/TPs Expert Summons”) for Prof Leung and Ir Kong to compile a supplemental joint expert report on liability for the third party proceedings to address on the following issue with proposal for consequential directions on exchange of provisional solo expert reports, arrangement for further without prejudice meeting of the experts, and compilation of their supplemental joint expert report on liability:

“How did the material alterations to [the Lift]

(a) in or about September 1997 including the following:- (i) installation of 3 fire-proof laminated panels on the back and side walls of [LC]; (ii) installation of a glass mirror on the upper half of the back wall of [LC]; (iii) installation of a stainless-steel panel and 5 sets of spot lights on the ceiling of the [LC]; (iv) installation of stainless-steel panels with reflective surface on the columns and beams of [LC]; (v) installation of 2 new lift doors made of stainless-steel panels with reflective surface; and

(b) in or about May 2002, for the replacement of the plastic floor tiles of the Lift by marble flooring

relate to the metal fatigue found in [FIR] of [EMSD].”

On the same day, D filed the Tang 4^th Aff in support of the D/TP Expert Summons.

38.  The Tang 4^th Aff claimed that by then documents were available to show when/how major alterations carried out prior to 2006 (ie the 27 Pages) caused substantial increase in the total load / weight of the Lift, which was important as (a) paragraph 12 of the Leung 2^nd Report explained that propagation of fatigue crack is determined by the S-N curve whereby S is the stress level suffered and N is the frequency of S occurrences, and (b) the experts on liability should give consideration to the major alterations actually done to the Lift in September 1997 (ie about 9 years earlier than 2006) with increased frequency of usage of the Lift with additional load/weight since 1997 (rather than since 2006).

39.  Later on, P revised her stance to the effect that the trial in the main action should proceed unless D was prepared to let interlocutory judgment to be entered or to undertake to let interlocutory judgment to be entered in favour of P immediately after the trial of the third party proceedings.

40.  On 20 October 2020, DoJ replied to DSols that EMSD had no record of any notification or application submitted to EMSD for renovation of LC of the Lift in 1997 and 2002.

41.  At the call-over hearing on 22 October 2020, I adjourned the Amend TPN and D/TPs Expert Summonses for argument, and granted leave for D (if so desired) to file/serve similar summonses in the main action for leave to re-amend the ADefence and to obtain supplemental joint expert report on liability.

42.  On 2 November 2020, D filed a summons (“Amend ADefence Summons”) for leave to re-amend the ADefence in the manner marked in green as per the draft annexed thereto (“Draft RADefence”) with proposal for directions concerning consequential amendments to other pleadings in the main action. On the same day, D filed a summons (“P/D Expert Summons”) for Ir Lo and Prof Leung to prepare a supplemental joint expert report on liability for the main action to address on the issue set out in paragraph 37 above with proposal for consequential directions on exchange of provisional solo expert reports, arrangement for further without prejudice meeting of the experts, and compilation of the supplemental joint expert report on liability.

43.  The Amend TPN and D/TPs Expert Summonses (collectively, “Third Party Proceedings Summonses”) as well as the Amend ADefence and P/D Expert Summonses (collectively, “Main Action Summonses”) were heard by this court on 11 February 2021 (“Hearing”).

44.  I now turn to the parties’ pleadings and draft amended pleadings to put the Third Party Proceedings Summonses and Main Action Summonses in context, but I will only focus the parts pertinent to the applications before the court.

V.     P’s CLAIM

45.  P claimed D held itself out as a company that specialised in lift repair/maintenance in Hong Kong, so D owed the following duties to all users (including P) of the Lift that D repaired/maintained:

46.  P claimed the Accident and her injuries were caused by D’s negligence and/or breach of common duty of care particularised as follows, and she further or alternatively relied on the doctrine of res ipsa loquitur:

VI.     D’s DEFENCE

47.  D claimed the Lift was installed by Chevalier in November 1986, and it started operation on 17 June 1987. Chevalier and Holake were the maintenance contractors of the Lifts from June 1987 to July 1997 and from July 1997 to 31 December 2007 respectively.

48.  D averred that in/about November 2005 Holake contracted to carry out renovation/upgrading of the Lift.[10] “[LC of the Lift] was also renovated with the addition of granite flooring, false ceiling and new walls over the original walls in order to change the Lift from a cargo lift to a passengers lift.” In subsequent investigation of the Accident, Holake did not produce any record, document or detail of the maintenance personnel for the period from July to December 2007. When D as maintenance contractor took over maintenance of the Lift as from 1 January 2008, neither Holake nor 1^st TP  informed/notified D of details concerning any major alteration even though (a) the Code of Practice for Lift Works and Escalator Works (“Code”) in 2002 and in previous editions issued by EMSD required Chevalier/Holake to keep logbooks of maintenance records and required RLC to notify EMSD of major alterations to the Lift, and (b) EMSD should have kept records of major alterations to the Lift by Chevalier/Holake. D claimed that after taking over as maintenance contractor, it properly repaired/maintained the Lift in accordance with the Code (including its updated edition) that gave guidance on matters relating to safety of lifts/escalators,[11] and it had kept proper maintenance record of the Lift, which record indicated D had not done any renovation/modification works to the Lift.

49.  D claimed that on/about 15 March 2010 D’s maintenance staff noted additional counterweight pieces had been attached to the Lift, and upon inquiry D was informed by 1^st TP’s staff there had been renovation works to LC of the Lift with approval obtained from EMSD in accordance with proper procedure, and upon such confirmation by 1^st TP D did not further investigate into the matter.

50.  D acknowledged its scope of work as maintenance contractor included maintenance of the traction machine of the Lift. On 26 September 2011, D carried out maintenance work on the traction machine of the Lift, including replacement of oil gasket seal. On 3 October 2011, the Lift resumed operation. On 4 October 2011, the traction machine had oil leakage problem, so D took the Traction Shaft to the workshop to have the oil seal replaced. On 7 October 2011, the Lift resumed operation. On 11 October 2011, oil seepage was found through the side of the sheave of the traction machine of the Lift. On 12 October 2011, D took the sheave component to the workshop for inspection, but no visual defect was found. On 20 October 2011, D took the Traction Shaft to the workshop for detailed inspection, and discovered a sleeve on the Traction Shaft with oil leakage found between the Traction Shaft and the sleeve. One end of the sleeve was then soldered to the Traction Shaft to seal the oil leakage. On 23 October 2011, the Lift resumed operation. In mid-December 2011, the traction machine again had oil leakage. D replaced the sleeve of the Traction Shaft without any soldering, and the problem of oil leakage was eventually eliminated. But D did not know the outer edge of the Traction Shaft had been trimmed, and/or the diameter had been reduced from 100mm to 90mm, which might have caused the fatigue crack. As shown in D’s maintenance records, D never made any alteration/modification to the Traction Shaft before the Accident on 9 November 2012.

51.  FIR did not indicate D had done any alteration/modification to the Traction Shaft[12] and/or D was responsible for the Accident. Further, apart from the lift manufacturer, EMSD would not have allowed any other RLC to undertake alteration/modification of the traction shaft of a lift.

52.  On/about 9 November 2012, EMSD’s engineers including Mr Ng inspected the Lift.[13] Subsequent investigation showed the Lift and Lift 8 were of the same model,[14] and there was a sleeve on the traction shaft of each of the Lift and Lift 8 both of which had modification works done before the Accident with loads of the counterweights increased. Since D did not carry out any modification/improvement works to the Lift since taking over maintenance work on 1 January 2008, so 1^st TP must have engaged the previous maintenance contractor(s) to carry out such modification/improvement works.

53.  Upon EMSD’s instructions, D engaged Victory to survey the weight of the Lift system, and it was found the total weight was 4,325kgs (see paragraph 4 above). Mr Ng noted such total weight and appended the survey report to FIR without any further comments. In its letter dated 14 March 2017, EMSD confirmed the Lift had been modified in 2006.

54.  Mr Ng in FIR stated that EMSD could not find any evidence of personal blame or culpability on D’s part, and that even though alteration/modification of major equipment had adversely affected the safe operation of the Lift, there was no evidence to indicate D, its staff or agents had done any alteration/modification to the Lift before the Accident or was in any way in breach of the Code.[15] After the Accident, EMSD did not give D any warning and did not take any action against D in its capacity as RLC.

55.  D therefore denied (a) it caused, permitted or allowed the alleged trimming of the Traction Shaft and/or was responsible for the Accident, (b) it had any knowledge of the alleged trimming of the outer edge of the Traction Shaft and the alleged reduction of its diameter from 100mm to 90mm, (c) the 2 ends of the sleeve were welded to the Traction Shaft at high temperature, (d) it could have discovered the alteration/ modification of the Traction Shaft from maintenance works to the Lift, (e) it could have foreseen the development of fatigue crack in Traction Shaft, and/or (f) it could have taken any measure to prevent the Accident. D also denied the doctrine of res ipsa loquitur was applicable to the Accident.

56.  D claimed that on/about 18 and 27 October 2011 it advised 1^st TP to replace the traction machine of the Lift and provided quotations to 1^st TP, but 1^st TP did not accept such advice/quotations. In/about November 2011, Guidelines for Modernising Existing Lifts (“Guidelines”) were distributed to lift owners and managers including the Incorporated Owners of the Building (“IO”) and/or 1^st TP, and the Guidelines aimed to help Responsible Persons for lifts (“RPs”) as defined in the Lifts and Escalators Ordinance Cap 618 (“LEO”) to implement enhancement/ modernisation solutions. D claimed the IO and 1^st TP as RPs had full discretion to decide whether or not to adopt the recommended enhancement solutions in the Guidelines, but D was only a RLC as defined under LEO and not a RP of the Lift. Further, at/about Lunar New Year in 2012 D proposed installation of rope grippers to the Lifts, but 1^st TP did not accept such proposal.

VII.    D’s CLAIM AGAINST TPs

57.  By the TPN, D claimed that if it were adjudged liable to P, it would be entitled to contribution/indemnity against:

58.  D reiterated its allegations in the ADefence, and averred that the 1^st and/or 2^nd TPs were negligent as follows:

VIII.   TPs’ DEFENCE (AND COUNTERCLAIM)

59.  TPs denied the relevance of the LEO and further denied they were RPs of the Lift under the LEO, and they pointed out that the Lifts and Escalators (Safety) Ordinance Cap 327 (“LESO”) (repealed on 17 December 2012) was still applicable at the time of the Accident and the LEO (particularly sections 12-15 thereof concerning RP’s duties) did not come into full operation until 17 December 2012. But TPs agreed that section 33 of LESO required the RLC engaged to carry out major alterations to any lift to notify EMSD of such lift works that were about to be carried out.

60.  TPs agreed (a) the Lift was installed in/about 1986 and should have started operation in/about 1987, (b) Chevalier was the maintenance contractor from June 1987 to July 1997, (c) Holake was the maintenance contractor from July 1997 to 31 December 1997, and (d) in/ about 2006 Holake contracted with TPs to (and Holake did) carry out improvement and upgrading works to the Lift (which was all along a passenger lift and never changed from a cargo lift to a passenger lift).

61.  1^st TP had power/duty under Clause 7.2(r) of the SDMC inter alia to enter into contracts and to engage/employ professional advisers, consultants and contractors touching or concerning the Building or the management thereof on behalfof 2^nd TP. In 2007, 1^st TP on behalf of 2^nd TP invited tenders for the Full Maintenance Contract for the Liftsfor the period from 1 January 2008 to 31 December 2009 (“2008 Contract”). On 31 December 2007, 1^st TP notified D that its tender for the 2008 Contract was successful. After expiry of such contract, D continued to be responsible for maintenance of the Lifts (including the Lift), and by a letter dated 23 April 2010 by 1^st TP on behalf of 2^nd TP, D was awarded upon tender the Full Maintenance Contract for the Liftsfor the period from 1 April 2010 to 31 March 2012 (“2010 Contract”). By a letter dated 25 April 2012, 1^st TP on behalf of 2^nd TP awarded D upon tender the Improvement Works for Cargo Lifts Nos. 1, 2, 5 & 6 and Full 3-Year Maintenance Contract of the Buildingfor the period from 1 April 2012 to 31 March 2015 (“2012 Contract”).

62.  TPs referred to various express terms in the 2008, 2010 and 2012 Contracts (collectively, “Contracts”), and averred that from 1 January 2008 to the date of the Accident D was contractually responsible for and in charge of inter alia the examination, maintenance and safety of the Lift, the discharge all statutory duties to ensure safety and safe operation of the Lift, and full compliance with all statutory requirements including but not limited to the LESO and the relevant Code as the RLC, registered lift engineer (“RLE”) and/or for and on behalf of TPs.

63.  TPs averred that D by submitting tenders for and being awarded the Contracts claimed to have necessary qualifications, expertise and knowledge in performing all duties/obligations under the Contracts, but on the other hand TPs did not possess relevant qualifications, expertise and knowledge, and relied on D to ensure safety and safe operation of the Lift and full compliance with all statutory requirements in relation thereto. If D required any information concerning the Lift,[16] it was for D to approach its predecessor Holake to obtain all needed information, and unless requested by D, TPs would not know what information D would require. Anyway, TPs had never refused any request to provide D with any information concerning the Lifts.

64.  Further, upon being awarded the Contracts D was required thereunder to carry out full/thorough examination of all 8 Lifts including the Lift, and from time to time D carried out regular examinations of the Lifts, so D ought to have been aware of alteration works done to the Lift and/or any safety issue relating thereto. Anyway, D admitted that at least by March 2010 (ie more than 2½ years before the Accident) it was aware that additional counterweight pieces had been attached to the Lift, and there had been renovation works to LC of the Lift.

65.  TPs admitted EMSD’s letter dated 3 January 2017 stated they had not received any notification of increased load/weight of the Lift’s CWT, but EMSD explained there was no requirement to notify EMSD for changing the load/weight of the CWT. Further, EMSD by letter dated 14 March 2017 stated the Code (2012 Edition) was not applicable to any modification of the Lift in 2006. But even if there had been any requirement to notify EMSD for changing the load/weight of the CWT (which TPs denied), it was the duty of Holake as RLC and not TPs (who had no knowledge of any such requirement for notification or in any absence of such notification) to notify EMSD in 2006.

66.  TPs denied the alteration works in 2006 had anything to do with the Accident. Further, the “alteration/modification of major equipment” in paragraph 7.3 of FIR only referred to modifications to the Traction Shaft. Paragraph 6.4 of FIR stated the failure of the Traction Shaft was caused by improper modification works that damaged the integrity of the shaft and thereby increased stress concentration at the weak point. As stated in FIR, D disassembled the Traction Shaft and applied shielded arc welding method to remedy an oil leakage problem in October 2011, and D again disassembled the Traction Shaft for sleeve replacement in mid-December 2011. TPs claimed the Accident was caused or contributed by D’s alteration/modification works to the Traction Shaft in 2011 and/or by D’s negligence and/or breaches of the Contracts in failing to (a) identify any safety issue relating to the Traction Shaft, (b) remedy/prevent the failure of the Traction Shaft, and/or (c) prevent the occurrence of the Accident.

67.  TPs put D to proof that the Guidelines were distributed to lift owners including TPs in/about November 2011. Anyway, D was required by the Contracts (and TPs relied upon D under the Contracts) to discharge all statutory duties to ensure safety and safe operation of the Lift and full compliance with all statutory requirements for all Lifts including the Lift.

68.  TPs claimed that by virtue of clauses 5.5 and 5.23 of the 2012 Contract D undertook/agreed to repair/replace any defective part of the Lift (other than caused by deliberate damage), to ensure full compliance with all safety requirements for the Lifts, and to upgrade all substandard equipment to satisfy the latest statutory requirements free of any further charge. As D was obliged to repair/replace the traction machine of the Lift at its own expense under the 2012 Contract, TPs did not accept D’s quotations dated 18 and 27 October 2011 to pay for replacement of the traction machine of the Lift. If replacement of the traction machine of the Lift was allegedly necessary to ensure safe operation of the Lifts (which TPs denied), D was required to replace the same under clauses 5.5 and 5.23 of the 2012 Contract free of further charge, and D was negligent and/or in breach of the 2012 Contract in failing to so replace such traction machine. Anyway, D had not advised TPs it would be unsafe to operate the Lift without replacing such traction machine or otherwise suspending or causing to be suspended the operation of the Lift in the absence of such alleged replacement of the traction machine.

69.  TPs denied that at/about the Lunar New Year in 2012 1^st TP declined to accept D’s proposal to install rope grippers to the Lifts. TPs claimed D had not submitted any such alleged report/proposal to TPs. But if the alleged installation of rope grippers was necessary to ensure safe operation of the Lifts (which TPs denied), D was required to install the same under clause 5.23 of the 2012 Contract that required D to ensure full compliance with all safety requirements for the Lifts and to upgrade all substandard equipment to satisfy the latest statutory requirements free of any further charge, and D was negligent and/or in breach of the 2012 Contract in failing to install the alleged rope grippers. In any event, D had not advised TPs it would be unsafe to operate the Lift without the alleged installation of rope grippers or otherwise suspending or causing to be suspended the operation of the Lift in the absence of the alleged installation of rope grippers.

70.  Further, D was precluded under clauses 4.12 and 5.12 of the 2012 Contract from claiming any contribution/indemnity from TPs as D was responsible to the full extent for any personal injury, loss and damage arising from D’s negligence or mistake, and should undertake to compensate TPs for any direct losses/expenses arising from any such negligence or mistake. It was said D was precluded from claiming any contribution/indemnity from TPs in the third party proceedings if P was able to establish any negligence or mistake on D’s part in respect of the Accident. But in the event of P failing to establish any negligence or mistake on D’s part in respect of the Accident, no issue of any contribution/indemnity from TPs shall arise. In the premises, the third party proceedings against TPs were misconceived.

71.  It is unnecessary for present purposes to describe TPs’ counterclaim against D in the third party proceedings.

IX.     D’s REPLY

72.  D claimed 1^st/2^nd TPs were the owners of the Lift as defined in LESO. Regardless whether the Lift was a passenger or cargo lift, renovation, improvement and upgrading of the Lift in November 2005 or in/about 2006 were major alterations under section 4 of the LESO as there was increase in the load/weight of LC/CWT of the Lift by about 1,000kgs that compromised the integrity of the Traction Shaft. Pursuant to section 13 of the LESO, if there were major alterations to a lift, the owner should cause the lift to be examined by a RLE, who should then deliver a certificate in prescribed form (including details of inter alia “Counterweight Safety Gear Tests and Counterweight Inspection”) to the owner, who in turn should submit it to EMSD for record within 7 days after receipt.

73.  D denied that TPs did not have relevant qualifications, expertise and knowledge and/or that TPs relied on D to ensure safety and safe operation of the Lift as well as full compliance with all statutory requirements in respect thereof, and averred that 1^st TP had project director(s) and/or engineer(s) who would examine and/or inspect the work done by D or its predecessors.

74.  D disagreed that it should approach Holake for information about the Lift and/or that TPs were not in a position to know what information D required. D averred 1^st TP should have kept a logbook for the Lift in prescribed form, and such logbook (which should record all inspections, maintenance and alterations of the Lift carried out by all lift maintenance contractors including D and its predecessors) was required by EMSD to be retained by the owner of the Lift as defined under the LESO.

75.  EMSD’s letter dated 2 January 2013 informed 1^st TP that Lift 8 (with same design/model as the Lift) had increased counterweight which might have compromised the integrity of the traction shaft, and asked 1^st TP to confirm if the Lift’s CWT also had been increased. D claimed it could be inferred that TPs had not submitted the certificates in prescribed form for major alterations to the Lift and Lift 8 at the end of 2005 or early 2006 to EMSD. In 2010, D’s staff was misled by 1^st TP’s staff into believing major alterations of the Lift in 2005/2006 had received proper approval from EMSD. D noted EMSD’s letters dated 3 January 2017 and thereafter did not address the issue of whether renovation/upgrading of the Lift in/about November 2005 amounted to major alterations as defined in section 4 of the LESO.

76.  D claimed it never carried out alteration/modification of the Traction Shaft, and remedial work that D carried out was to stop the oil leakage and to prevent damage to the Traction Shaft. D also claimed repair/replacement of the traction machine of the Lift was not within the terms of the 2012 Contract for the maintenance of the Lift even though such contract included upgrading of and major alterations to Lifts Nos 1, 2, 5 and 6 (but not to the Lift or Lift 8).

77.  D averred TPs owed P tortious liability for negligence, so by virtue of section 7(1) of the Control of Exemption Clauses Ordinance Cap 71 (“CECO”), TPs could not exclude/restrict their liability for personal injury resulting from negligence.

78.  It is unnecessary for present purposes to deal with D’s defence to TPs’ counterclaim in the third party proceedings.

X.   TPs’ REJOINDER

79.  TPs admitted 2^nd TP (but not 1^st TP) was the owner of the Lift as defined in the LESO. But TPs denied (i) any improvement/ upgrading works to the Lift in November 2005 or in/about 2006 were major alterations as defined under section 4 of the LESO, (ii) there was increase of about 1,000kgs in the load/weight of the Lift’s LC/CWT and/or (iii) the integrity of the Traction Shaft was compromised. TPs averred that:

80.  TPs admitted the provisions in sections 13(1)-(2) of the LESO, but denied 1^st TP had any project director(s) and/or engineer(s) who would examine/inspect the work done by D or its predecessors. TPs averred they did keep/maintain or cause to be kept/maintained a logbook pursuant to section 27B of the LESO which only required details of works carried out in accordance with sections 12, 13, 19, 21, 22, 23 and 24 thereof and in accordance with an order under section 25 thereof to be entered by RLE and RLC, including D and Holake. The logbooks were in prescribed form as approved by EMSD, and were provided by TPs’ lift contractors including D and Holake. The current logbook was kept/ maintained at the management office of the Building for RLE and RLC, including D and Holake, to enter necessary information. Old logbooks were previously kept/maintained at a storeroom of the Building, but D had not asked TPs for inspection of the same. Upon taking over from Holake, D should have obtained from Holake all information in connection with the Lift necessary for discharge of its contractual/ statutory duties, and D was negligent and/or in breach of its contractual/ statutory duties in having failed to do so.

81.  TPs denied that in 2010 D’s staff was misled by 1^st TP’s staff, and TPs repeated their pleas in the AD&C.

82.  TPs claimed section 7(1) of CECO would not have prevented them from relying on the terms of the 2012 Contract to preclude D from claiming any contribution/indemnity from them in the third party proceedings. TPs did not seek to rely on any contractual term to exclude or restrict any liability for personal injury towards P (if any) which TPs denied.

XI.   DRAFT ATPN

83.  The proposed amendments in the Draft ATPN were essentially as follows:

XII.    DRAFT RADEFENCE

84.  The proposed re-amendments in the Draft RADefence were essentially as follows:

XIII.   PLEADINGS AND EXPERT EVIDENCE

85.  Mr Lin, counsel for TPs, submitted that:[17]

86.   Whilst Mr Wong, counsel for D, and Mr Shum, counsel for P, had little disagreement with the above propositions as broad principles, what truly mattered would be the application of such broad principles (if relevant) to the present case-specific context of the main action and the third party proceedings that required interaction among pleadings, discovery and expert evidence.

87.   Here, there was fairly little dispute over the circumstances of the Accident (see paragraphs 2, 8 and 9 above). Rather, the disputed issues on liability turned almost entirely on technical matters with the initial issue being the cause for the Lift to uncontrollably ascend in over-speed to hit the lift shaft structures at/about the 28^th (top) floor when it was supposed to descend to the ground floor. This was a factual albeit technical issue, but was probably easily answered as Mr Ng, Ir Lo, Prof Leung and Ir Kong all accepted it was due to the fracture failure of the Traction Shaft.[19] The anterior issue on liability was the finer question of what caused the Traction Shaft to suffer fatigue fracture and become broken (“Causation Issue”), which issue must be determined by the trial court so as (a) to ascertain the scope of (i) the relevant tortious duty of care that D owed to P (if any) and (ii) the relevant tortious duty of care and contractual/statutory obligations (if any) that TPs owed to D (if any), and (b) whether there had been any breach thereof. In my view, although the Causation Issue would be a factual question for the trial court, such issue would turn almost entirely on technical matters, which explained why all parties in the main action and the third party proceedings obtained expert reports on liability (and causation).

88.   Generally speaking, on technical/skilled matters (whether engineering, medical or other disciplines), experts on liability (and causation) at trial have (a) an explanatory/didactic function in educating the lay court on technical facts/matters pertinent to the relevant issue(s) in dispute,[20] and (b) a further function in giving opinion to assist the lay court in deciding whether acts/omissions of the responsible person(s) and/ or party(ies) would constitute negligence and/or breach of contract. But where the claim/defence in the litigation turn essentially on technical/ skilled matters rather than lay facts, the experts on liability (and causation) have another important (but not often emphasised) function at the pre-trial stage, ie their expert opinion on liability (and causation) will be required for the parties to properly shape their respective pleaded case.

89.   If formulation of a party’s case depends on lay facts/matters, such party is expected to properly plead all material facts in his pleadings based on factual materials known or available to him from enquiries, discovery and witnesses. Not so if such party’s case depends on technical/ skilled matters. Whilst he may have some knowledge or may have made some preliminary investigation (if he is in the same profession, trade or discipline) to raise a prima facie case on his pleadings,[21] his pleaded case cannot be complete until he has to hand his expert report on liability (and/or causation) that will enable him to frame and plead the fullness of his case on technical/skilled matters that have to interface with the eventual expert evidence to be adduced at trial.[22] Thus, in a case where the issue of liability (and/or causation) turns on technical/skilled matters, the usual course is for each party to commission solo expert report on liability (and/or causation) to aid proper formulation of his pleadings, which therefore explains why, say, parties in medical negligence cases are required to serve “any expert medical report relied on as to liability and causation” with their pleadings.[23] There is no carte blanche for obtaining/adducing expert evidence on liability (and/or causation), but leave of the court will be readily granted where the party(ies) satisfy(ies) the court that such expert opinion on liability (and/or causation) is necessary, relevant and of probative value for the just and proper resolution of the parties’ dispute.

90.   But that is not the end of the matter. More expert reports may have to be obtained in the course of pre-trial case management,[24] but as alluded to in the above paragraph, leave of the court is required for commissioning such supplemental, additional and/or joint expert reports on liability (and/or causation) that are intended to be adduced as expert evidence at trial. As and when such supplemental, additional and/or joint expert reports become available, each party should revisit his pleadings to see if necessary amendments are required so as to properly plead/aver the fullness of his case on liability (and/or causation) to be pursued/adduced at trial.[25] Notwithstanding the laudable underlying objectives under Order 1A rule 1 of the RHC, a party who applies reasonably promptly to amend his pleadings upon evolution of expert opinion on liability (and/or causation) as the litigation develops (in contra-distinction to matters inherently within his own knowledge but has not previously pleaded) should not be judged too harshly. Whilst case management considerations are quintessentially relevant in the post-CJR era, they should be viewed in relevant cases through the prism of the necessary involvement of expert evidence, and the constraint that the expert renders his opinion independently rather than at the whim of the litigant.

91.   This brings me to another facet of the formulation of a party’s case where the issue of liability (and/or causation) turns on technical/skilled matters and hence on expert opinion on liability (and/or causation), namely, that such expert opinion is good insofar as the factual assumptions upon which it rests are satisfactorily proved at trial. [26] So it behoves a party who wishes to adduce expert opinion on liability (and/or causation) to inter alia (a) provide full/accurate factual assumptions for his expert to found his opinion, and (b) adduce sufficient evidence to prove such factual assumptions at trial. If (i) such factual assumptions are incomplete/inaccurate or (ii) are not satisfactorily proved at trial, the expert opinion that rests on unconvincing factual foundation may weaken or crumble, which cannot bode well for the relevant party in a case that turns on technical/skilled matters.

92.   Consequently, it is imperative for a party who has to frame his pleaded case by drawing on expert opinion as to liability (and/or causation) to provide all necessary factual assumptions for his expert to render full/accurate opinion to facilitate such party to properly plead the technical material facts. In gathering such necessary factual assumptions, the first port of call must the relevant party’s own knowledge, information and documents,[27] but this exercise extends to other information/ documents.[28] In this respect, witness statements and discovered documents from other party(ies) in the litigation are another important source of relevant/necessary documents to form factual assumptions for the expert on liability (and/or causation) to render full/accurate opinion, which in turn enables the relevant party to properly plead his case.

93.   This exercise is aided by the well-known Peruvian Guano test for determining the “relevance” of discoverable documents.[29] On such test of “relevance”, the real question is whether the documents to be discovered are relevant to the issues between the parties to the litigation or, putting it in another way, to the “questions in the action”.[30] There has been suggestion that the issues or questions must be those identified in the pleadings, but it has been held in Thorpe v Chief Constable of Greater Manchester Police[31] that matters can be “in question” or be the subject of controversy between the parties even though not expressly raised on the pleadings. At p 833, Neill LJ said as follows:

“…… It is clearly established, however, that ‘the matters in question’ cover wider ground than the issues as disclosed in the pleadings. Thus a party is obliged to disclose any document which it is reasonable to suppose contains information which may enable the party applying for discovery either to advance his own case or to damage that of his adversary or which may fairly lead to a train of inquiry which may have either of these two consequences. It follows that discovery is not necessarily limited to documents which would be admissible in evidence.”

94.   Often in cases where the question of liability (and/or causation) turns on technical/skilled matters, the claimant lacks knowledge or full knowledge of the matters that may form relevant and useful factual assumptions for his expert on liability (and/or causation). P in the present action would be a prime example; she probably had no idea or not much of an idea about the Traction Shaft let alone all the technical niceties that went to its properties, function, operation, maintenance and failure.[32] Here, P was content to merely sue D, so she largely relied on factual assumptions drawn from FIR. But using a hypothetical example as illustration, had P chosen to join TPs as further defendants in the main action (as she had once thought to do at an earlier stage – see paragraph 12 above), she would probably have to rely on statement evidence and/or discovered documents from D and TPs to form factual assumptions for Ir Lo to render his expert opinion, and eventually to prove those factual assumptions at trial. And likewise in the third party proceedings, D maintained (even though TPs disagreed) its knowledge of any renovations/upgrading in relation to the Lift before 2008 (when it took over as maintenance contractor of the Lifts) was not much better in view of alleged paucity of information from Holake/TPs, so it was also reliant on proper disclosure of information/documents by TPs and/or on enquiries with EMSD.

95.   It will descend into an unhelpful circular argument for a party to argue that discovery is not required to be made unless the pertinence of certain documents has been precisely identified in the pleadings, but the other party (having no idea of the existence of such documents that may advance his case or may lead to a train of inquiry which may have such consequence on a “question in the action” albeit not precisely identified in the pleadings) cannot in the absence of discovery put the same as factual assumption to his expert on liability (and/or causation) to obtain expert opinion that will in turn allow such other party to plead a full/clear case that precisely raises the issue. This leaves the other party between a rock and a hard place, ie he cannot get discovery of useful documents unless he precisely identifies the issue in the pleadings, but he cannot so plead unless he has those documents for seeking expert opinion, which, if favourable, will allow him to plead the issue.

96.   In my view, neither substantive nor procedural law would so prejudice a party, and the clear/obvious solution is the Peruvian Guano test for discovery as explained above. It must be remembered that quite unlike the court which deals with legal liability and causation by making findings and drawing inferences on the balance of probabilities, professional/skilled experts deal with technical certainty so that if they are unable to give opinion with certainty or if there is insufficient basis to give opinion on any expert issue, they have to frankly say so in their expert reports,[33] which again highlights the importance of providing full/ accurate factual assumptions for the experts.[34] Using the medico-legal example in footnotes 33-34 above, the defendant may not know about the plaintiff’s childhood disease/injury, and will not be able to tell his own medical expert or to plead the same , but if the defendant disputes causation and suggests that the impugned surgery cannot be the likely or only cause of the indexed medico-legal incident, the plaintiff will have to make discovery of the documents referred to in footnote 34 above on Peruvian Guano basis because he is required to disclose all documents that may fairly lead to a chain of inquiry on the issue of causation, and more so if general expert opinion is already available to the effect that pre-existing disease/injury is a common possible cause for the weakened state of the relevant body part.

97.   The above discussion assumes that after obtaining relevant discovery a party may provide new or revised factual assumptions to his own expert on liability (and/or causation) for further opinion and, depending on the opinion to be obtained, may then apply for leave to amend his pleadings. But it becomes more complex when there are already court-imposed expert directions for the parties’ solo experts on liability (and/or causation) to have a without prejudice meeting and/or to compile a joint report setting out their agreements and disagreements. It is true that, unlike the situation of a joint approach to expert evidence by having the parties’ respective experts compile a joint report (as in the case of joint medical expert reports on the quantum issue here), parties can still communicate privately with and have access to their own experts on liability (and/or causation) both before and after the without prejudice meeting.[35] But, as explained in Fung Chun Man v Hospital Authority & anor,[36] a party who wants to adduce at trial any further or supplemental expert opinion from the expert on liability (who must first reduce his opinion in writing in an expert report) has to seek leave of the court to do so. This is particularly so when after the 1^st round of solo expert reports on liability (and/or causation) by the parties’ experts, the court has already seized case management control over expert evidence by exercising its discretion to grant expert directions that (a) limit the scope/ issues of the expert evidence on liability (and/or causation) to be adduced, and (b) require the experts to engage (and here they have already so engaged) with each other in a without prejudice meeting to work out their agreements/disagreements on the issues in (a) above to be set out in a joint report. In such circumstances, a party who wishes to bespeak further expert evidence that travels beyond the constraints imposed by court-ordered issues/ambit of expert evidence will require leave of the court, and the court in debating whether leave should be granted will consider (i) the cogency/usefulness of the proposed further or supplemental expert issues in helping to resolve the disputed trial issues in the litigation, and (ii) other case-specific case management considerations such as cost, proportionality, fairness, delay and other underlying objectives.

98.   With the above considerations in mind, I turn to the applications before me.

XIV.   AMEND TPN AND D/TPs EXPERT SUMMONSES

99.   It appeared that the essential purpose of the proposed amendments in the Draft ATPN was to introduce the averments that in/about September 1997 and May 2002 TPs contracted with and assigned Holake to renovate/upgrade the Lift (see paragraph 83(a) above) resulting in significant increase in the load/weight of LC of the Lift by about 380kgs (see paragraph 83(b) above), but TPs failed to report to EMSD such major alterations in/about 1997/2002 (rather than in/about 2006 as originally pleaded) (see paragraph 83(c)-(d) above), such that D had no knowledge of such major alterations (which were not notified to EMSD, not in the logbook for the Lift and not notified by Holake/TPs).

(a)  D’s contentions

100.   Mr Wong submitted that the proposed amendments in the Draft ATPN did not raise any new case. D already pleaded in the TPN (a) there were major alterations to the Lift prior to 2008 (including those that involved increase in the load/weight of LC/CWT) that compromised the integrity of the Traction Shaft, and (b) TPs failed to inform D of such major alterations (see paragraphs 58(b) and 72-75 above). It was said that given the previous incomplete state of TPs’ discovery, D was led to assume the major alterations involving increase in the load/weight of LC of the Lift were carried out in/about 2006 being the only disclosed pre-2008 renovations notified via Form 7 to EMSD (see paragraphs 15 and 53 above), but D was at the material time unaware because it was not so informed and there was no certificate to such effect submitted to EMSD (see paragraphs 34(a) and 72 above). It was only through D’s determined forensic enquiry that TPs quite recently disclosed/discovered the 27 Pages, which in turn revealed more detailed information as to the renovations/upgrading of LC of the Lift in 1997/2002, and which led to the Amend ATPN Summons for putting D’s already pleaded case on the Causation Issue in its proper temporal context. Mr Wong argued the proposed amendments were material to the issues of liability and/or causation between D and TPs, but they were nothing more than to bring the TPN in line with documentary evidence recently revealed by TPs.

101.   Mr Wong submitted the proposed amendments were prima facie supported by the following, which tended to show that it was the excess load/weight of the Lift that caused the fracture failure of the Traction Shaft, but that D should not be faulted because it had no knowledge of the same in the absence of notification by Holake/TPs and/ or lack of records with EMSD (when there should have been such notification/records available to D):

(b)  TPs’ contentions

102.   On the other hand, Mr Lin submitted that in paragraph 6.2 of the Leung/Kong Jt Report Prof Leung opined that (a) material alterations in 2006 should have included increase in the load/weight of CWT of the Lift by 500kgs (with corresponding increase in the load/weight of LC of the Lift by 380kgs for “optimal balance”), and (b) the total increase in weight of 880kgs for the Lift was substantial enough to result in the fatigue fracture found in FIR, so D’s present proposal to plead it was the 1997/2002 renovations rather than the 2006 renovations that increased the load/ weight of the Lift was a new/distinct case “inconsistent” with Prof Leung’s present opinion, and D’s present attempt in the D/TPs Expert Summons to obtain supplemental expert report(s) on liability was a 11^th hour effort to move litigation goalposts to include the 1997/2002 renovations.

103.   But Mr Lin also argued that D should not be allowed “to shift its case to “tailor-make” its pleadings in order to fit [Prof Leung’s] opinion so that it would sound more “probable” or “supported””, which was impermissible “reverse engineering”, especially when the Yeung EMSD Statement[37] that was already available to D (and indeed also to Prof Leung) showed Holake had carried out renovations in 1997 to “更換[the Lift]地下外門及內門同時更換地膠及旁板” such that D had plenty of opportunity since the discovery of such statement in December 2016 (see footnote 37 above) to investigate into the matter of the 1997 renovations.

104.   It was said that D’s attempt to adduce further expert evidence on its new case was in effect nothing more than speculative “fishing expedition”. Mr Lin argued the 27 Pages would not support D’s proposed amendments because they did not say (a) the additional counterweight bricks were added to CWT of the Lift during the 1997/2002 renovations and/or (b) the 1997/2002 renovations increased the total load/weight of LC of the Lift by 380kgs. Mr Lin also argued that the proposed amendments were vague and lacking in particulars as to, say, (i) what was the actual increase in load/weight of LC of the Lift as a result of the 1997 renovations and the 2002 renovations, and (ii) what was the causal link between the Accident and the increase in load/weight of LC of the Lift by about 380kgs, so the proposed amendments were embarrassing and prejudicial to TPs, and it would be no answer for D to say TPs could later seek further and better particulars.

105.   Mr Lin submitted that D’s attempt to blame TPs for the Accident via the proposed amendments was “a non-starter and [was] bound to fail” as D admitted (see Mr Chan’s 2^nd witness statement dated 7 March 2019) it was aware in March 2010 there had been renovations to the Lift with additional counterweight pieces added by the former maintenance contractor. Mr Lin contended that:

“…… In the premises, it is quite unclear how D could claim contribution and/or indemnity against [TPs] by alleging that [TPs] had failed to report the 1997 and 2002 Renovations to the EMSD and failed to inform D about the particulars of the major alterations prior to 2008. All along, D was required under the Contracts to thoroughly examine and be aware of the alteration works that had been carried out to the Lift and all the safety issues relating to the Lift. ……”

106.   Mr Lin further argued that in any event D’s present averments as to the 2006 renovations in the TPN and the proposed amendments in relation to the 1997/2002 renovations were immaterial/ unnecessary for determining the dispute between D and TPs in the third party proceedings: (a) if D successfully resisted P’s claim in the main action, no issue of contribution/indemnity would arise, but (b) if D were found liable to P in the main action (ie D was under a duty to discover/ identify safety issues in relation to the Lift, but was negligent in failing to discover the alterations to the Lift and/or to identify any safety issue in relation to the Traction Shaft), still no question of contribution/indemnity would arise because by such finding of duty D could not blame TPs for not having informed D. Mr Lin submitted that “[from] another perspective, if the Court finds that [TPs] were under a duty to inform D of the alterations made to the Lift, then D would not be negligent in its failure to discover the alterations and the safety issue arising therefrom in the first place”.

107.   Thus, Mr Lin contended that the proposed introduction of the 1997/2002 renovations to the TPN would raise new focus/dimension, but such proposed averments were speculative and unnecessary/irrelevant for the third party proceedings, which D should not be allowed to plead at such late stage when TPs would have great difficulty in investigating into the matter (since the 1997/2002 renovations went back more than 18-23 years) and in scrambling up a response in the run-up period until trial, and when a great deal of effort would have to be expended in amending pleadings and in obtaining further expert reports, and possibly in adducing further statement evidence and in commencing fourth party proceedings against Holake with risk of vacating the trial dates.[38]

108.   I pause here to note there was just under a year until the trial, and in the authorities referred to in footnote 38 above the proposed amendments to pleadings were first raised shortly before or almost at trial (Chan Kwan Yin Shirley & anor), 8 days before trial (Tang Wai Lam, the sole executor of the estate of Siu Mak Cheung, deceased), and 5 weeks before trial (Chan Ying Wai). In Li Shiu To, no trial date had been fixed, and the proposed amendments were allowed.

109.   Further, none of the proposed amendments in those cases were dependent on discovery from the other party(ies) and/or consequent expert evidence, and there was either no or no good reason for delay in the relevant applications to amend pleadings:

110.   Returning to Mr Lin’s submissions, he contended it was unfair for D to say TPs were late in disclosing the 27 Pages that related to the 1997/2002 renovations since discovery was limited to relevant matters in question by reference to the pleadings, and D did not plead the 1997/2002 renovations in the main action and/or in the third party proceedings for documents pertaining to such renovations to fall within the scope of discovery. In any event, the Yeung EMSD Statement that was already disclosed in December 2016 (see footnote 37 above) stated “[Holake] 於1997年更換[the Lift] 地下外門及內門同時更換地膠及旁板”, so “[if] it is D’s case that the 1997 and 2002 Renovations had increased the weight of [LC] of the Lift, they could have pleaded the same as early as when they issued the [TPN] back in September 2017”, and the court should not be sympathetic to D’s present applications made at a late stage that would raise new dimension/focus and that would shift the litigation goalposts despite time/opportunity having been made available for D to put forward the fullness of its case.[39]

(c)  P’s contentions

111.   Mr Shum made submissions to support TPs’ opposition of the Third Party Proceedings Summonses because Mr Wong fairly acknowledged that if these summonses were dismissed, D would not be able to pursue the Main Action Summonses.

112.   Mr Shum submitted notwithstanding D’s argument that TPs’ late discovery of the 27 Pages revealed for the first time alteration works in 1997/2002 (ie prior to 2006) would have increased the load/weight of LC of the Lift, which D believed to have bearing on the issue of liability between D and TPs, there was no expert evidence on liability (whether in draft form or otherwise) to support such new case, which in the absence of supporting evidence was wholly speculative. It was said at this late stage the court would require some supporting evidence before D would be allowed to amend its pleadings to add a new case.

113.   Mr Shum argued that in fact D’s bare belief was contradicted by D’s letter to 1^st TP dated 28 November 2012 to the effect that it carried out regular checking/maintenance of the traction machine of the Lift and completed the 5-year load test of the Lift on 13 February 2012 under the supervision of its registered engineer with no abnormality found, so Mr Shum suggested it was incredulous for D to assert in 2021 (and without supporting evidence) that the 1997/2002 renovations adding load/ weight to the Lift was the “possible” cause of the Accident.

114.   Mr Shum acknowledged “[it] is a substantive right of a party to bring his full case before the Court provided he can do so without prejudice to the other party that cannot be compensated by costs”, but he argued that “if the new case he seeks to advance is weak or appears unlikely to succeed, then that factor must weigh in the balancing exercise between the need to ensure a just and proper adjudication of the real dispute between the parties and the need to ensure cost effectiveness and economy, expedition, proportionality, fairness between the parties and the proper use of the Court’s resources”.[40] Mr Shum urged the court to be wary of allowing a party to amend pleadings to raise a new case and to serve additional factual/expert evidence once a case has reached the stage of setting down (and here trial dates had been fixed). Mr Shum submitted the Amend TPN Summons should not be allowed in light of these principles, the prejudice to TPs (even though the trial was just under a year away), fairness, justice, expediency and saving of time/costs, especially when P had incurred substantial time/costs and endured a long wait for trial.

115.   Mr Shum noted the order of Master Roy Yu dated 28 January 2019 did not direct the parties’ experts on liability to address on how the material alterations to the Lift in/about 2006 related to the metal fatigue found in FIR; rather, such order only asked the experts on liability to state whether or not they were in agreement with particular contents of FIR. It was said such expert directions would not justify obtaining supplemental joint expert report. Further, given D’s admitted discovery of additional counterweight bricks to CWT of the Lift in 2010, which should have “led to a reasonable chain of inquiry which in all likelihood would have revealed the problems and issues therewith”, Mr Shum submitted D should have looked into and made enquiries on its new case long before 2020. Mr Shum therefore argued that the D/TPs Expert Summons should also be dismissed.

(d)  Discussion

116.   In my view, consideration of the Draft ATPN must start with a proper understanding of P’s expert evidence on liability in the third party proceedings. The Leung 2^nd Report:

117.   In respect of (e) above, although Ir Kong (a) in paragraph 4.3.3 of the Kong Report suggested that (i) D “allowed to implement the wrong method by fixing the old sleeve to the main shaft with high welding temperature and subsequent heat treatment of new sleeve to the main shaft by local factory”, and (ii) “[those] procedures may adversely affect the material property of main shaft and led to failure of the shaft eventually”, and (b) in the Kong Comments on paragraph 15 of the Leung 2^nd Report opined that “the welding heat is the possible cause of the failure since the welding temperature was over 1000ºC as estimated so that the sleeve and shaft can be joined together” with the result that “both ends with weld joint of sleeve had damaged the shaft” (and heat damage was shown on the broken portion of the Traction Shaft seen in the photographs in FIR), Prof Leung and Ir Kong eventually agreed in paragraph 7.1 of the Leung/Kong Jt Report that “the welding temperature damage on the metallic material that was resolved at the expert meeting [ie without prejudice meeting between the experts] as not important”.

118.   The Kong Comments on paragraph 15 of the Leung 2^nd Report opined that “[the] reason for the broken end of the shaft at the portion of diameter of 115 mm was due to the stress concentration at that part after trimming of shaft as well as high welding temperature”, but in light of the agreement between Prof Leung and Ir Kong evident in paragraph 7.1 of the Leung/Kong Jt Report as explained in the above paragraph, Ir Kong’s current opinion on the cause of fracture failure of the Traction Shaft was essentially “stress concentration at that part after trimming of the shaft” (my emphasis).

119.   On this, (a) Prof Leung noted that trimming of the Traction Shaft was not recorded and it was reasonable for D to assume that the first sleeve existed in the original design (see paragraph 116(c)-(d) above), which went to D’s case that it did not know and would not have known about the trimming of the Traction Shaft so that there was no breach of duty in identifying the trimming and safety issues arising therefrom and that it could not have taken any measure to prevent the Accident (see paragraphs 55 and 58 above), and (b) whilst Prof Leung in paragraphs 10-11 of the Leung 2^nd Report (see paragraphs 10-11 of the Leung 1^st Report in paragraph 21 above) agreed stress concentration could cause fatigue crack initiation, he opined that stress concentration was not necessarily created by machine damage and could be created by improper design (eg “[stress] concentration occurs when the radius is small”) notwithstanding perfect machining, and here it was borne out by “the L-shaped radius made by the vertical surface of the 155mm diameter and the horizontal surface of the 90mm diameter after trimming, i.e., the radius at the meeting point of the vertical and horizontal surfaces” (which trimming D averred it did not know and would not have known about), so Prof Leung (disagreeing with Ir Kong) was of the view that crack initiation could take place at any place along the machine-trimmed Traction Shaft and not necessarily at the spot where it actually fractured.

120.   More importantly, Prof Leung opined that fatigue crack initiation alone was not enough to result in fracture failure of the Traction Shaft because for such failure to occur there must have been crack propagation (ie crack growth). According to Prof Leung’s explanation of the S-N curve in paragraph 12 of the Leung 2^nd Report (see paragraph 12 of the Leung 1^st Report in paragraph 21 above), fracture will occur as a matter of time when S (ie stress level) that exceeds the critical threshold of the endurance limit is coupled with N (ie frequency of S occurrences). Ir Kong had no objection on the aforesaid S-N curve for consideration of the endurance limit.[41] So, in relation to the Lift, the question was whether there was such increase in the load/weight of the Lift that (a) the stress intensity exceeded the endurance limit (b) over a period of time caused crack growth/propagation leading to fatigue fracture of the Traction Shaft.

121.   For Prof Leung, in respect of (a) above, quite irrespective of the 1997, 2002 and 2006 renovations, there was objective expert basis for the view that there had been increase in the load/weight of the Lift to move S beyond the endurance limit. According to paragraph 13 of the Leung 2^nd Report (see paragraph 13 of the Leung 1^st Report in paragraph 21 above), as seen in “Photo No 1” of FIR,[42] Prof Leung noted 10 new counterweight bricks at 50kgs each, so there had been increase of 500kgs in load/weight to CWT of the Lift. Prof Leung opined that for “optimal balance” the load/weight of LC of the Lift had to correspondingly increase by 380kgs, so from an engineering perspective there would have been total overall increase in the load/weight of the Lift by about 880kgs, which increase as compared to the total load/weight of the Lift (2,938kgs) based on Victory’s weight measurements represented 30% increase in the load/weight on the Traction Shaft that Prof Leung opined was substantial enough to “move S away from the endurance limit”. For Prof Leung, in respect of (b) above, usage of the Lift with such increased load/weight over the years (whether since 2006 and logically more so if usage was since 1997/2002) would have caused crack growth and eventual fatigue fracture of the Traction Shaft resulting in the Accident.

122.   Thus, there was already expert opinion from Prof Leung that there must have been increase in the load/weight of LC of the Lift because such increase was inevitable from the engineering perspective to achieve “optimal balance” against the known addition of 10 counterweight bricks to CWT of the Lift. Indeed, Ir Kong also agreed there was increase in the load/weight of LC of the Lift to “counterbalance” the counterweight fillers (or bricks) of CWT of the Lift except that (a) he opined there should be equivalent additional load/ weight (say, 500kgs rather than 380kgs) for LC to “counterbalance” equivalent additional load/weight (say, 500kgs) for CWT, but (b) since there was no site measurement/indication as to the mass of the counterweight fillers (bricks) he opined the additional load/weight of the counterweight fillers (bricks) to CWT of the Lift might be about 300kgs “so as to counter balance [LC] decoration”.[43] Taking Ir Kong’s views in (a)-(b) above together, they suggested that if the increase of the load/ weight of CWT of the Lift as a result of the addition of the counterweight fillers (bricks) might be about 300kgs, then equivalent additional load/ weight for LC of the Lift might also be about 300kgs.

123.   Thus, the consensual opinion by both Prof Leung and Ir Kong appeared to be that there should have been corresponding increase in the weight/load of CWT and LC of the Lift for “counterbalancing” or “optimal balancing” purpose, and given the known increase of 10 counterweight fillers (bricks) to CWT of the Lift, the essential difference between Prof Leung and Ir Kong appeared to be whether the actual increase in the load/weight of LC of the Lift was 380kgs or it might be 300kgs (see paragraphs 121-122 above). Further, Ir Kong accepted that an increase “in dead weight of lift is a kind of major alteration by [LESO or LEO]”, and “formal application of resumption permit by lift contractor via submission of Form 7 [under LESO] or LR7 [under LEO] was required”.[44]

124.   Thus, in my view, there had not been shifting of D’s expert opinion or indeed D’s case, which was that overall increase in the load/ weight of LC/CWT of the Lift[45] caused S to exceed the endurance limit and over the years crack growth/propagation eventually led to fracture failure of the Traction Shaft. Thus, D’s case was that but for the aforesaid crack growth/propagation (in respect of which D claimed there was no breach of duty/contract on its part), fatigue fracture of the Traction Shaft would not have occurred.

125.   Given the currently available and essentially consensual expert opinion in the third party proceedings of engineering “counterbalance” and/or “optimal balance” between increase in the load/ weight of LC of the Lift and that of CWT of the Lift, the next relevant matter would be to identify as factual assumption for the experts rather than expert opinion by the experts the event/activity would have resulted in increase in the load/weight of (a) CWT and (b) LC of the Lift.

126.   As for (a) above, notwithstanding the difference of opinion between Prof Leung and Ir Kong as to whether the additional load/weight to CWT of the Lift should be 500kgs or 300kgs (see paragraphs 121-122 above), the factual assumption for the increase in the load/weight of CWT of the Lift posed little problem because the addition of 10 counterweight fillers (bricks) to CWT of the Lift was seen in “Photo No 1” in FIR and referred to in paragraphs 9 and 14 of Mr Chan’s 2^nd witness statement dated 7 March 2019.

127.   As for (b) above, given that Prof Leung and Ir Kong consensually opined there would have been some increase in the load/ weight of LC of the Lift despite their difference over whether it should be 380kgs or might be 300kgs (see paragraphs 121-122 above), the relevant factual assumption was to identify the event/activity that might result in such increase in the load/weight of LC of the Lift for the experts on liability to assess/validate their opinion based on skilled knowledge and experience. Of course, TPs put D to proof of such alleged event/activity at trial, but at this stage the court was not concerned with ultimate proof at trial but with the availability of information/documents for the experts on liability to harness as factual assumptions and for D to responsibly plead its case.

128.   On this, Ir Kong in the Kong Comments on paragraph 13 of the Leung 2^nd Report noted no relevant Form 7 / LE7 had been submitted to and there was no record with EMSD (even though “increasing in dead weight of lift is a kind of major alteration by [LESO or LEO] ……”),[46] and he opined the additional load/weight to LC of the Lift was likely to have been added during the installation stage upon final testing and the commissioning period with full load testing and measurement.[47]

129.   But Prof Leung opined it was the renovations/modifications to the Lift that increased the load/weight of the LC (which increase in dead weight of the Lift was, according to Ir Kong, “a kind of major alteration by [LESO or LEO]”) prior to 2008 (since D who took over as maintenance contractor in 2008 did not carry out such renovations/ modifications), but they were not reported to EMSD and/or made known to D.

130.   Given (a) the objective evidence that the load/weight of CWT of the Lift was increased by the 10 counterweight fillers (bricks), and (b) the consensual expert opinion that the load/weight of LC of the Lift was increased for “counterbalance” or “optimal balance” purpose, and more importantly, given (c) the existence of the 1997, 2002 and 2006 renovations (as clearly known by now) that took place after 1987 when the Lift commenced operation and before 2008 when D became the maintenance contractor, and (d) the absence of any notification/report to EMSD of any major alterations as to increase in dead weight of the Lift (whether by way of statutory forms or otherwise), I find the professional surmises of Ir Kong (ie increase in the load/weight of LC of the Lift was done during the installation/commissioning periods) and Prof Leung (ie such increase in the load/weight of LC of the Lift was done during post-operation renovations) based on their technical/skilled understanding as to the installation, commissioning operation, renovations and modifications of lifts to be arguable,  and much would turn on evidence/ proof to be adduced by the parties at trial and the court’s eventual factual findings (if any) as to when increase in the load/ weight of LC of the Lift took place, and why there had not been any relevant notification/application to EMSD, which factual findings would determine the vitality of the factual assumptions on which differing expert opinion rested.

131.   But on the anterior question of formulation of proper factual assumptions for the experts, the starting point must be that there was no factual information/documents at all that showed the additional load/ weight to LC of the Lift was “added during the installation stage upon final testing and commissioning period with full load testing and equipment”. Indeed, paragraph 7.2 of the Leung/Kong Jt Report stated that “[the] influence of the addition of nearly 500kg decoration weight and 500kg counter weight on [the Lift] remains an issue to check with manufacturer if the original design had such allowance” (see paragraph 26 above).

132.   At the time when D framed its third party claim in the TPN, post-operation renovations to the Lift prior to 2008[48] known to D with documented particulars and/or submission of relevant statutory forms to EMSD (bearing in mind that it was D’s case that the overall increase in the load/weight of the Lift amounted to major alterations) were the 2006 renovations. So in the TPN D (against the background of the matters in paragraph 130(a)-(d) above (except for the 1997/2002 renovations which D claimed not to have particular knowledge at that time)) specifically referred to such 2006 renovations but at the same time complained about the non-notification about the increase in the load/weight of the Lift.

133.   Although the Yeung EMSD Statement and Mr Yeung’s witness statement dated 12 March 2019 referred to replacement of the floor panels of the Lift with marble flooring (see paragraphs 15-16 above), there was no particularised information as to what was the precise scope/ ambit of such works and what materials were used as the former statement merely referred to replacement of “地下外門及內門” and “旁板” of the Lift in 1997, but the latter statement mentioned mirrors were added.

134.   It was suggested that discovery in March 2010 of the additional counterweight fillers (bricks) to CWT of the Lift should have led to a reasonable chain of enquiry which in all likelihood would have revealed the problems/issues therewith (see paragraph 115 above). Whilst the question whether in March 2010 D had any statutory, common law or contractual duty to undertake such chain of enquiry and whether such enquiry if undertaken would have revealed the problems/issues therewith as alleged might be matters for trial, it was all along D’s case that it could not have and was not required under common law or the Contracts to discover for itself the 1997/2002 renovations done to the Lift, especially when there should have been documentary trail with EMSD for major alterations to alert D. It is not for this court at this stage to form any definitive view on such dispute.

135.   Further, I am unable to see how D could have done more when it prepared its pleadings, served statement evidence and instructed its expert on liability in the third party proceedings on the basis that it was led to believe it was not possible to make further investigations because (a) EMSD had no record of the 1997 renovations, and (b) even though the Yeung EMSD Statement claimed there was documentary record of such renovations, the subsequent Yeung Witness Statement dated 12 March 2019 confirmed the relevant documentary records were no longer retained due to long lapse of time. In my view, there was at that stage paucity of particulars for D to responsibly plead that the 1997 renovations contributed to significant increase in the load/weight of the Lift. Indeed, D did not even know then that some renovations took place not in 1997 but in 2002. Bearing in mind that from an engineering perspective there would have been increase in the load/weight of LC of the Lift to “counterbalance” or “optimally balance” the additional load/weight to CWT of the Lift, with no evidence of pre-operation increase in the load/weight of the Lift, and with paucity of particulars for the 1997/2002 renovations, it was little wonder that Prof Leung and/or D relied on the then available factual assumption of the 2006 renovations for the increase in load/weight of the Lift, but complained of lack of notification to EMSD and/or to D.

136.   But the specific statement in the Yeung Witness Statement dated 12 March 2019 that renovations to LC of the Lift were no longer retained due to long lapse of time was in fact wrong because TPs all along retained the 27 Pages that included documents pertaining to the 1997/2002 renovations, which error was compounded by the fact it was Mr Yeung himself who prepared the Table and who collated/compiled the 27 Pages. This only came to light through the forensic diligence of Mr Tang (see paragraphs 30-31 above) even though, I must say, the absence of any description as to the information in the last column in the Table might not have alerted a less enquiring mind of the possibility of 27 pages of supporting documents that were yet to be sighted.

137.   The now available 27 Pages revealed detailed particulars of the scope/ambit of works, materials used and costs expended in the 1997/2002 renovations, so now there would be basis for D to responsibly plead the fracture failure of the Traction Shaft on the basis of such renovations. It was said that such proposed plea was vague and “fishing” because the 27 Pages did not precisely say the increase in the load/weight of CWT of the Lift was added in 1997/2002 or that the 1997/2002 renovations increased in the load/weight of LC of the Lift by 380kgs. But proof was not necessarily by direct evidence. If the new pleas were allowed, I believe D would be asking the court to infer and conclude from the overall circumstances, including (a) the load/weight of CWT of the Lift was increased by 500kgs (according to Prof Leung’s opinion) prior to 2008, (b) the load/weight of LC of the Lift was increased by 380kgs for “optimal balance” (according to Prof Leung’s opinion), (c) the very nature of the 1997/2002 renovations suggested the works would have increased the load/weight of LC of the Lift (according to the 27 Pages but subject to further opinion by the experts on liability), and (d) there was no information that increase in the load/weight of LC of the Lift was made during the installation/commissioning periods, that the increase in the load/ weight of LC of the Lift in (b) above would have been caused by the 1997/2002 renovations in (c) above. Even without further expert report from Prof Leung, I am unable to say such plea was speculative or embarrassing; indeed, I go further to say that such plea was arguable, but whether it would succeed to convince the trial judge would be a matter for trial.

138.   I also do not agree the proposed amendments raised any new focus/dimension. It had always been D’s case and the tenor of Prof Leung’s opinion that the additional load/weight to CWT/LC of the Lift caused crack growth/propagation and eventual fatigue fracture failure of the Traction Shaft, and that it was the additional counterweight fillers (bricks) that increased the load/weight of CWT and the pre-2008 renovations that increased the load/weight of LC. The problem for D and Prof Leung was that prior to discovery of the 27 Pages they had not been provided with fullness of information as to the 1997/2002 renovations for D to responsibly plead them as material facts and to provide them as relevant factual assumptions for Prof Leung for him to assess his propositions and to render his full opinion. It was for Prof Leung to give opinion (if he could) on whether from an engineering viewpoint the scope/ambit of works, materials used and costs incurred in 1997/2002 renovations as shown in the 27 Pages could enlighten whether the load/weight thereby added to LC of the Lift would be about 350kgs or at least would sufficiently move S beyond the endurance limit. Had the 27 Pages been available to D at an earlier time, I have no doubt they would have been provided to Prof Leung and Ir Kong, and as experts on liability they would/should assist the court by saying whether the information therein would allay some/all of their stated queries and/or concerns (as expressed in their current expert reports) as to whether such increase in the load/weight of LC of the Lift (when they had already opined there would have been some increase in weight/load of LC of the Lift due for “counterbalance” or “optimal balance” purpose) could be technically established. To say there was a shift in focus/dimension from the 2006 renovations to the 1997/2002 renovations was to lose sight of the above-mentioned foundation of D’s case and the tenor of Prof Leung’s opinion made a time when they were constrained by non-discovery of the 27 Pages pertaining to the 1997/2002 renovations that restricted the existing pleaded case of D and the factual assumptions for Prof Leung.

139.   On the above analysis, I disagree that the proposed amendments were “inconsistent” with Prof Leung’s opinion or alternatively it was tailor-made to “fit” Prof Leung’s opinion to make it sound more “probable” or “supported”. In my view, it could not have been any “reverse engineering” because as explained above, quite irrespective of the 1997, 2002 and 2006 renovations, Prof Leung was able to and did opine from an engineering perspective there had been increase in the load/weight of LC of the Lift by 380kgs, and the pertinence of these renovations was for correlation of factual assumptions to such engineering expert opinion and for facilitating pleading of material facts to permit proof of such assumptions at trial. The so-called “inconsistency” and/or “reverse engineering” was because D was hobbled by the non-availability of the 27 Pages until quite recently.

140.   But Mr Lin submitted TPs had no obligation to make discovery of the 27 Pages, which he claimed was irrelevant on D’s existing pleadings. I disagree. In my view, the 27 Pages plainly pertained to a “matter in question” in the present action, ie how the increase in the load/weight of the Lift came about, which increase in load/weight was, on D’s case, what led to the eventual fracture failure of the Traction Shaft. On the Peruvian Guano test requiring disclosure of documents that may fairly lead to a chain of inquiry on such “matter in question”, the 27 Pages were plainly discoverable as tending to show there were earlier renovations that added load/weight to the Lift, which might show crack propagation (ie increased load/weight of the Lift that would move S away from the endurance limit and longer period of usage of the Lift with additional such load/weight since 1997 instead of 2006 that would add to N frequency), especially when the existence of the 27 Pages were known to TPs but not to D. It was no answer for TPs to say D could have made its own enquiries when the Yeung Witness Statement dated 12 March 2019 erroneously stated documentary records of such earlier renovations were no longer retained. Since the 27 Pages were properly discoverable, then quite irrespective whether it took D a while to put a finger on the same, TPs in the first place had an obligation to discover such documents as being relevant in the Peruvian Guano sense, and could not defer such disclosure and complain about delay and lateness when D later stumbled on such documents.

141.   Mr Lin submitted the proposed amendments were unhelpful in that they would be irrelevant (a) if D successfully defended P’s claim in the main action then no issue of contribution/indemnity would arise, but (b) if D were found liable to P in the main action then D could not blame TPs for its own liability to P (see paragraph 106 above). If Mr Lin were right in such argument, then D’s pleadings as to the increase in the load/weight of the Lift (irrespective whether D relied on the 2006 renovations or the 1997/2002 renovations) would have been without merit at all. Yet not only was there no attempt to strike out such existing pleas, TPs engaged D in pleadings (even up to the ARejoinder), statement evidence and expert evidence in the expectation that such dispute would be tried in due course. Under the TPN, it was D’s case that if D were liable to P, D failed in its duty to P because TPs had been negligent vis-à-vis D. P might argue D had a duty to discover the problems or safety issues with the Lift and to take appropriate remedial steps, but D (if found liable to P) claimed it was unable to discharge its duty to P because TPs kept it in the dark. Whether TPs could successfully resist such claim by asserting it had no such duty to D and/or no breach of such duty (if any) would be a matter for trial. Here, at issue before me was not the fundamental cause of action in the third party proceedings but whether D should be allowed to rely on the 1997/2002 renovations rather than the 2006 renovations for its claim.

142.   By reason of the above analysis, I disagree with Mr Shum’s submissions in paragraphs 112-113 above that the proposed amendments were speculative and not supported by any expert opinion. Instead, I find the existing expert evidence supportive of D’s contention that there was increase in the load/weight of the Lift, and the recent discovery of the 27 Pages allowed D to now responsibly plead its proper case. The fact D wrote to the 1^st TP on 28 November 2012 in the manner set out in paragraph 115 above would not necessarily establish the proposed amendments were hopeless since such letter must be read in the context of D’s case that (a) in 2010 the 1^st TP assured D of the propriety of the addition of the 10 counterweight fillers (bricks) to CWT of the Lift, (b) in 2010 D did not know the full particulars of the 1997/2002 renovations and the 27 Pages were not yet available to D, and (c) D expected what it believed to be major alterations of increase in dead weight of the Lift to be notified to EMSD but there was no such notification/certificate/report. I cannot say the proposed amendments which set out D’s case more fully in light of further discovery from TPs would be unlikely to succeed.

143.   In my view, D should be allowed to amend the TPN in the manner marked in red as per the Draft ATPN. P claimed it was far too late to force TPs to scramble up a response. But I note there was just under a year until trial, which would be time enough for D/TPs to obtain further expert report on the 1997/2002 renovations in light of the 27 Pages. In any event, as explained in Part XVI below, the parties at the Hearing agreed to obtain a tripartite joint expert report by Ir Lo, Prof Leung and Ir Kong covering broad expert issues that should have been canvassed by them as experts on liability. In such circumstances, I am unable to see how TPs would be prejudiced by the need to obtain further expert report. As explained in Part XIII above, expert opinion is only as good as the vitality of the underlying factual assumptions. In my view, in light of the present expert opinion of Prof Leung and Ir Kong as explained above, it would be plainly relevant and necessary for such experts to consider the recently disclosed 27 Pages with detailed particulars of the works/ materials for the 1997/2002 renovations in fully formulating their views to assist the court.

144.   As for Mr Lin’s allusion to prejudice that might arise from investigation into the 1997/2002 renovations, I find that D issued the Third Party Proceedings Summonses with reasonable alacrity after it had access to the 27 Pages, obtained TPs’ Answer to its interrogatories and unsuccessfully approached TPs for consent to such applications. Mr Yeung who compiled the Table and the 27 Pages was an available witness. If he had any further recollections about such renovations, it would not be difficult and there would be time for him to supplement his existing statement evidence. Mr Yeung had confirmed that TPs’ other documentary records (if any) were no longer available. The current logbook for the Lifts is obviously available. Earlier logbooks were stored in a storeroom of the Building (see paragraph 80 above). Enquiries with EMSD had been exhausted. In the year ahead, there would be time enough for D to make enquiries with and seek discovery against Holake if needed.

145.   Whilst I agree the trial that had been set down to commence on 9 March 2022 is a milestone event which this court is most unlikely to move or vacate notwithstanding the current developments (and any attempt by TPs to pursue fourth party proceedings must take this into account), it must be remembered that under section 6 of the Limitation Ordinance Cap 347 time would still run for TPs to commence proceedings to claim contribution against Holake if so required after the trial in the present action, but to debar D from raising the proposed amendments will permanently truncate the fullness of D’s third party claim. Thus, even taking into account the case management considerations and underlying objectives (including the real possibility that TPs might not be able to pursue fourth party proceedings in the present action) as well as the need for fair and just resolution of disputes, I find it necessary and just to allow the proposed amendments in the Daft ATPN and to allow the 1997/2002 renovations be put to the experts in the third party proceedings and to seek their further opinion thereon.

XV.   AMEND ADEFENCE AND P/D EXPERT SUMMONSES

(a)  D’s contentions

146.   Mr Wong explained that due to P’s change of heart not to temporarily stay the main action pending resolution of the third party proceedings (presumably following TPs’ refusal to adopt such approach) and TPs’ recent disclosure of the 27 Pages, D found it necessary to further amend the ADefence to set out the material facts outlined in Part XII above, which proposed re-amendments were in line with the proposed amendments to the TPN. Mr Wong submitted that for similar reasons a supplemental expert report should be obtained from Ir Lo and Prof Leung to address on the increase in the load/weight to LC of the Lift in relation to the 1997/2002 renovations, which D claimed to be major alterations that were not notified to EMSD / D.

(b)  P’s contentions

147.   Mr Shum submitted that the Amend ADefence Summons merely sought to plead the 1997/2002 renovations as allegedly having contributed to the cause of the Accident, and that it appeared D believed the 1997/2002 renovations in addition to those in 2005 would have a bearing on the liability of D/TPs, ie D was not saying the 1997/2002 renovations were the sole cause of the Accident in 2012 (ie after the Lift was in regular use at least for 10 years since the 2002 renovations).

148.   This point could be easily dealt with. Whilst D retained its averments in respect of the 2005/2006 renovations in the Draft ATPN and Draft RADefence, it was made clear in those draft pleadings that it was the 1997/2002 renovations and not the 2005/2006 renovations that increased the load/weight of LC of the Lift (see paragraph 83(b) and (d) and paragraph 84(b) above). All along, D pleaded that “[LC] was renovated with addition of granite flooring and false ceiling and new walls to change the Lift from a cargo lift to a passenger lift” (see paragraph 83(b) and 84(b) above), but that was without the benefit of detailed particulars evident from the 27 Pages. Upon the availability of the 27 Pages, D was able to plead the particularised renovations in 1997/2002 in place of the pre-existing averments, and to rely on the actual renovations in 1997/2002 for its assertion that there had been an increase in the load/weight of LC of the Lift. In short, the proposed re-amendments were to bring D’s pleadings in line with the now available documentary evidence.

149.   Mr Shum next argued the proposed amendments were irrelevant to P’s claim against D in the main action. It was said the Lift was not safe for use at the time of the Accident, and P basically claimed D in holding itself out as an experienced maintenance contractor failed to maintain the Lift in safe condition for use by lift-users, and therefore it was in breach of or failed to discharge its common law tortious duties to lift-users, which breach/failure caused the Accident. In particular, P claimed (a) D was negligent in failing to replace the traction machine of the Lift when it knew the diameter of the Traction Shaft had been trimmed from 100mm to 90mm to allow insertion of the sleeve, which trimming resulted in stress concentration and metal fatigue that caused the facture failure of the Traction Shaft that led to the Accident, and (b) suggested D knew these matters as it was D who requested TPs to replace the traction machine and the Traction Shaft. So if it were found at trial that (i) it was the trimming of the diameter of the Traction Shaft from 100mm to 90mm to allow insertion of the sleeve that resulted in stress concentration and metal fatigue that caused the fracture failure of the Traction Shaft, and (ii) D was negligent in failing to cause the traction machine to be replaced/repaired to render the Lift safe for use, then D would have been liable to P and whether there were other contributing causes of the Accident and/or contributing tortfeasors jointly and severally liable together with D were irrelevant when the main action (in contra-distinction to the third party proceedings) was not concerned with the apportionment of liability among contributing causes/tortfeasors.

150.   Mr Shum argued that the Main Action Summonses appeared to be attempts in the main action to mirror the Third Party Proceedings Summonses and the proposed amendments in the Draft ATPN to cast blame on TPs (and/or others) for not making known the 1997/2002 renovations to D as possible cause of the Accident, but the proposed amendments were irrelevant in the main action in the sense that if P failed to prove its pleaded case against D on negligence/causation in relation to the traction machine, P’s claim would fail irrespective of the proposed amendments, which proposed amendments would only serve to unnecessarily increase costs/efforts for P and lead to disproportionate time/costs to be expended in the main action. Mr Shum submitted such argument was reinforced by the fact P would not be contributorily negligent (indeed there was no plea to such effect in the Draft RADefence), so the apportionment of liability among contributing causes/tortfeasors which might be pertinent for the third party proceedings had no bearing in the main action that concerned one issue, ie whether D was liable to P in the manner as pleaded. On such basis, it was said to be expedient to limit issues and expert evidence in the main action, and the Main Action Summonses should be dismissed.

(c)  Discussion

151.   In my view, Mr Shum’s arguments focused on P’s claim, ie the alleged cause of the fracture failure of the Traction Shaft due to trimming and D’s alleged duty to replace the traction machine, but at this pre-trial stage this court cannot take such a blinkered view without keeping in mind D’s defence.

152.   I can deal with one matter shortly. In relation to P’s allegation that D was negligent in failing to replace the traction machine, it was D’s case that it did suggested that to TPs who declined such suggestion (see paragraph 56 above). This was a factual issue that had been pleaded.

153.   As regards P’s claim the fatigue fracture of the Traction Shaft was caused by the trimming of such shaft resulting in stress concentration and metal fatigue, D in its ADefence denied P’s claim, put her to proof, and claimed it had no knowledge of the trimming of the Traction Shaft. This was bolstered by Prof Leung’s opinion that it was reasonable for D to be unaware of the modification by trimming to allow insertion of the sleeve and to assume that the sleeve was the original design.

154.   But additionally D wished to positively aver that even though the trimming and/or reduction in diameter of the Traction Shaft might lead to fatigue crack (see paragraph 50 above), the fatigue fracture failure of the Traction Shaft was caused by the increased load/weight of the Lift for which it was not liable (ie crack propagation as referred to by Prof Leung). This was not mere finger-pointing at a co-tortfeasor for contribution/indemnity and/or a matter of apportionment of liability; rather it was D’s contention that P’s claim against D would fail not merely P would fail to prove her case but because D was able to establish a distinct “but for” element (for which D claimed it was not liable) without which the fatigue fracture of the Traction Shaft would not have occurred. I see no reason why D should not be allowed to plead such positive defence, which had already been alluded to in the ADefence but which now required revision to set out its fullness due to the recent availability of the 27 Pages.

155.   For reasons discussed in Part XIV above, I am not persuaded that the defence put forward in the proposed re-amendments to the ADefence were without merit. I have discussed at length Prof Leung’s opinion in the Leung 2^nd Report and in the Leung/Kong Jt Report. The same or similar opinion was given by Prof Leung in the Leung 1^st Report and the Lo/Leung Report. It would be useful to cite his succinct observation in item 4(4) of the Lo/Leung Report that “[the] root cause of failure was the additional load of 880kg to the [Traction Shaft] ……” (see paragraph 24 above). Mr Shum reminded that the Lift remained in use for at least 10 years after the 1997/2002 renovations, but I do not see such submissions as detracting from the merits of the proposed re-amendments for Prof Leung opined it was a combination of S level and N frequency (ie the length of time that the Lift with its additional load/weight was in use) that led to the propagated fracture failure of the Traction Shaft.

156.   Mr Shum complained about the lateness of the proposed amendments, but I have found such delay was not due to D’s own making but due to the late availability of the 27 Pages that finally allowed it to responsibly plead the proposed re-amendments and to put such documentary evidence to the experts on liability. It was true that P would have some investigation to make and perhaps some discovery to seek, but in this case D had made clear it did not have information as to the 1997/2002 renovations, and there was the fortuity of the third party proceedings such that any further information/documents from those proceedings would be made available in the main action. It had been agreed at the Hearing that documents/witnesses in both the main action and the third party proceedings would be common evidence in both proceedings (although the disputed issues to be resolved would be different). As for further expert evidence, I reiterate the matters in paragraph 139 above and Part XVI below. Taking into account the need for just resolution of disputes and other case management considerations and underlying objectives, bearing in mind there was just under a year to trial, I find it necessary and just to allow the proposed re-amendments in the Daft RADefence and to allow the 1997/2002 renovations be put to the experts on liability in the main action and to seek their further opinion thereon.

XVI.   EXPERT REPORTS

157.   As explained in paragraphs 18-19 above, Master Roy Yu directed the parties in the main action and the parties in the third party proceedings to render expert reports on following issues:

158.   To start, FIR contained technical/skilled opinion by Mr Ng. But normally it is not necessary for any party to seek leave to adduce Mr Ng’s opinion in FIR at trial as expert evidence because each party (if it wished) would have obtained leave to adduce her/its own comprehensive expert evidence on liability and causation, and FIR (including Mr Ng’s opinion therein) would be part of the background in relation to the investigation of the Accident which the experts on liability would refer to in setting out their own findings and their own opinion on liability and causation.

159.   The experts in their solo reports were expected to conduct comprehensive review information/documents provided to them and to give their own comprehensive opinion (and reasons therefor) on liability and/or causation. If there are any aspects of the expert issues in respect of which they were unable to give opinion with any certainty or at all, they would be obliged as experts to say so and give explanations in their reports.

160.   This is important because, as I have explained in paragraph 88 above, experts on liability and causation serve a dictatic function apart from giving expert opinion. Here, I would have expected the experts on liability to have explained (on instructions, information and documents available to them and so far as they were able) inter alia the structure of the Lift system, its original design, current structure, modifications, properties, installation, commissioning, function/operation of relevant parts/equipment, examinations, maintenance, repairs and major alterations, and to have further explained who was responsible for what matters (in light of the contractual, industry/trade, EMSD and statutory requirements). I would also have expected the experts on liability and causation to give an account of the failure of the Lift that caused the Accident, and to explain (as far as they could) the immediate cause(s) for such failure, the facts/ matters concerning the Lift system that led to those immediate cause(s), and what acts/omissions by which responsible person(s)/party(ies) resulted in the direct/indirect causes of such failure. In doing so, the experts might refer to FIR to illustrate and/or elaborate their own views on the above matters, but their comments on certain parts of FIR could not replace their primary duty as experts on liability and causation to set out their own views.

161.   Then I would have expected the experts on liability and causation in the main action to explain the standard of care expected of a professional maintenance contractor under statutory requirements, relevant terms of contract and common obligations in the trade/industry under the usual Bolam requirements, and to give opinion whether D had failed to meet such threshold. Likewise, the experts on liability and causation in the third party proceedings would also have been expected to address on the above matter, and also (if they could from their skilled knowledge/ experience in dealing with lifts in buildings owned by lift owners and managed by property managers) on what corresponding duties/obligations lift owners and property managers owed under statute, contractual terms and/or industry/trade.

162.   Once the experts on liability and causation have completed their solo reports, if so directed by the court, I would have expected them to attend without prejudice meeting and to engage with each other in working out their agreements and disagreements, and to set out their consolidated opinion in a joint report. The joint report should set out the matters agreed, and identify the areas of disagreement, set out the respective expert opinion on each area of disagreement and their reasons for disagreement. Where concession was made with revision of views expressed in earlier solo reports, this should be made clear in the joint report with reasons given.

163.   Expert opinion on liability and causation to be useful to the lay trial court should follow the above approach. To simply critique certain parts of FIR avoids the dictatic function of expert opinion, and raised uncertainty as to (a) whether the experts on liability/causation agreed or disagreed with other parts of FIR that might form the underlying factual or engineering basis upon which Mr Ng gave his opinion, and (b) whether the experts’ own opinion on liability and causation was based on their own findings and views in contra-distinction to their mere opinion on Mr Ng’s technical/skilled opinion.

164.   But the narrowed approach adopted in paragraph 157 above led the experts on liability and causation to look upon their task as a critique of Mr Ng’s comments in sections 5-7 of FIR. Consequently, as evident from the Leung/Kong Jt Report, Prof Leung and/or Ir Kong asked EMSD to provide information/proof of various matters in those parts of FIR,[49] asked for clarification on “weld” referred to in FIR and “燒低溫銅焊” referred in paragraph 9 of Mr Keung’s witness statement dated 2 May 2017,[50] and sought technical information/drawing of the original geometry of the Traction Shaft from the original manufacturer and comparison thereof with other Lifts in the Building.[51] This was borne out even more starkly in paragraphs 4.2.1-4.2.5, 4.2.7, 4.2.7 and 4.2.11 in the Kong Report, which question-raising exercise formed the bulk of his “opinion” on sections 5-7 of FIR. These concerns illustrated other similar ones that generally beset the existing expert reports (including those in the main action), and there was no present need for this court to be exhaustive given counsel’s agreement to obtain further tripartite expert report on liability and causation (see paragraph 168 below).

165.   Further, because the experts on liability and causation in compiling their reports were asked to focus their comments on sections 5-7 of FIR rather than on their own opinion on liability and causation in the manner explained in paragraphs 159-162 above, they often stopped short giving reasoned opinion on relevant expert issues. An illustration can be found in paragraphs 5.1 and 5.3 of the Leung/Kong JT Report where Leung opined that the sleeve (revealed by ultrasound examination in October 2011) could not have been discovered on normal inspection, and Kong disagreed by saying D was required to carry out full/thorough examination of all Lifts of the Building and from time to time to carry out regular examination of the Lift, and as “a professional lift contractor who was engaged to provide professional lift maintenance services under the Contracts, [D] should have sufficient technical knowledge, expertise and support to verify the case of the main shaft problem”. But these assertions (rather than reasoned opinion) by the experts would not tell the court (a) what was required to be done on a “normal inspection”, (b) why by reason of the configuration of the Traction Shaft and/or the work to be done on a “normal inspection” D would not have noticed (as Prof Leung claimed) or would have noticed (as Ir Kong asserted) the insertion of the sleeve and the trimming of the shaft, (c) whether D should have discovered the trimming of the Traction Shaft when the sleeve was discovered in October 2011 or whether the sleeve/trimming should/could  have been discovered earlier and the reason therefor, and (d) what D should have done when it discovered the sleeve in October 2011 or had the sleeve/trimming been discovered earlier. To say D as a professional lift contractor should have sufficient technical knowledge, expertise and support to verify such matters would not tell the parties/court much.

166.   Although paragraph 4.3.3 of the Kong Report stated “the worn sleeve and main shaft should be replaced properly so as to rectify the oil leakage and maintain sufficient strength of the motor shaft during the period of 21 October 2011”, this was not repeated in the Leung/Kong Jt Report, and it was unclear whether this meant (a) the whole Traction Shaft with sleeve should be replaced by a new one or (b) repairs could be done to fix the old sleeve to the Traction Shaft if “high welding temperature” and “heat treatment” were not involved. If the interpretation was (a) above, its vitality would turn on a factual dispute over whether replacement was proposed and/or declined. But if the interpretation was (b) above, there was further uncertainty because the Leung Comments on paragraph 4.3.3 of the Kong Report disputed use of “high welding temperature” and “heat treatment”, and in paragraph 7.1 of the Leung/ Kong Jt Report Kong agreed “[the] welding temperature damage on the metallic material …… was resolved at the expert meeting as not important”. Prof Leung and Ir Kong did not elaborate further on “not important”, which seemed to suggest Ir Kong no longer maintained paragraphs 4.2.8 and 4.3.3 of the Kong Report and the Kong Comments on paragraph 15 of the Leung 2^nd Report. The above matters were put forward as illustration of similar concerns in various aspects of the available expert reports.

167.   Another concern that drove the need to revisit the available expert reports was the case management approach adopted towards obtaining expert reports in the main action and in the third party proceedings. Since Prof Leung as D’s expert on liability for both the main action and the third party proceedings was required to give his full and comprehensive opinion to the court, it is difficult to see how his opinion in the Leung 1^st Report and the Lo/Leung Jt Report could be shut out from the third party proceedings, and how his opinion in the Leung 2^nd Report and the Leung/Kong Jt Report could be shut out from the main action, when his opinion in those reports touched on the same or similar subject matter. It was even more worrying if there was segregation of Prof Leung’s viva voce evidence at trial for the main action and for the third party proceedings given the real risk of different/conflicting evidence and outcomes.

168.   All of the above matters cried out for a tripartite expert report by Ir Lo, Prof Leung and Ir Kong on the expert issues in dispute along the lines as explained in paragraphs 159-162 above. I am glad to say that at the Hearing Mr Shum, Mr Wong and Mr Lin all agreed to such approach, and they also sensibly agreed for the trial court to try the main action and the third party proceedings together with lay/factual evidence adduced for common use at both sets of proceedings, but leaving counsel to submit on and the trial court to determine the common and distinct issues in the main action and in the third party proceedings.

169.   For the new tripartite report to be obtained, the parties should sensibly agree on a common bundle of documents for use by the experts on liability, joint instructions to such experts that give guidance on the proper approach to compilation such tripartite expert report, and joint expert questions to be put to such experts. With opportunity now to prepare a comprehensive tripartite expert report, the parties experts on liability should also be reminded to incorporate all their opinion in the tripartite joint report so as to obviate the need to cross-reference to their various earlier reports and thus save parties’ efforts/time at trial (but without prejudice to the parties’ right to cross-examine the experts on their earlier reports). It would also obviate the need to debate the status and admissibility of the “provisional” Lo Report, Leung 1^st/2^nd Reports and Kong Reports as well as the Leung/Kong Comments. The experts, if they could, should also be asked to prepare a bilingual glossary of relevant technical terms since Chinese technical terms were used in the factual witness statements but the experts’ reports were compiled in English.

170.   That leaves one further matter for consideration, ie what would be the status of FIR at trial. At present, there were no directions for leave to adduce Mr Ng’s opinion expressed in FIR as expert opinion at the trial in the present action. I note D had issued a writ of subpoena ad testificandum against Mr Ng. Could any party call Mr Ng to give opinion evidence without expert directions? Could the party who called Mr Ng to give evidence cross-examine him? The need for viva voce evidence from Mr Ng should be re-visited by the parties after the tripartite joint expert report on liability is obtained. If Mr Ng should be called to explain his views in FIR, would allowing him to adopt FIR as his evidence in chief and all parties to cross-examine him be a fairer approach in the particular context of this case when the parties’ experts on liability have all commented on parts of FIR?

XVII. CONCLUSION

171.   In respect of the Amend TP Summons, I grant the following orders in the third party proceedings:

172.   In respect of the Amend TPN Summons, there be a costs order nisi that (a) 1^st/2^nd TPs shall pay D costs of and occasioned by the Hearing insofar as it concerned the Amend TPN Summons to be taxed if not agreed, and (b) save for (a) above, costs of and occasioned by the amendments (including costs of the Amend TPN Summons) be paid by D to 1^st/2^nd TPs (including all costs reserved, if any) to be taxed if not agreed.

173.   In respect of the Amend ADefence Summons, I grant the following orders in the main action:

174.   In respect of the Amend ADefence Summons, there be a costs order nisi that (a) P shall pay D costs of and occasioned by the Hearing insofar as it concerned the Amend ADefence Summons to be taxed if not agreed, (b) save for (a) above, costs of and occasioned by the amendments (including costs of the Amend ADefence Summons) be paid by D to P (including all costs reserved, if any) to be taxed if not agreed, and (c) P’s own costs be taxed in accordance with Legal Aid Regulations.

175.   As for the D/TPs Expert and P/D Expert Summonses, D had generally succeeded on such summonses as I have allowed D to obtain further expert report on liability in relation to the 1997/2002 renovations. However, in light of the matters raised in Part XVI above, it would be more appropriate to obtain a rolled-up tripartite joint expert report on liability and causation that addressed the matters in Part XVI above and also the 1997/2002 renovations. I therefore direct the parties to jointly write to the court within 14 days from the date of this order to propose case management directions at the formal order under the D/TPs Expert and P/D Expert Summonses.

176.   I grant a costs order nisi under the D/TPs Expert Summons that (a) 1^st/2^nd TPs shall pay D costs of and occasioned by the Hearing insofar as it concerned the D/TPs Expert Summons to be taxed if not agreed, (b) save for (a) above, costs of and occasioned by P/D Expert Summons (including all costs reserved, if any) be costs in the cause of the third party proceedings.

177.   I grant a costs order nisi under the P/D Expert Summons that (a) P shall pay D costs of and occasioned by the Hearing insofar as it concerned the P/D Expert Summons to be taxed if not agreed, (b) save for (a) above, costs of and occasioned by the P/D Expert Summons (including all costs reserved, if any) be costs in the cause of the main action, and (c) P’s own costs be taxed in accordance with Legal Aid Regulations.

XVIII. POSTSCRIPT

178.   It is an underlying objective of the RHC for the courts to encourage settlement. Trial dates have been set in this case, and the aim of this decision is to deal with the outstanding case management steps to ready the case for trial. That said, I hope that the above discussion will also help the parties see more clearly not only their own respective stance, but also the stance/evidence of the other parties to help them take stock of the present litigation. As fairly acknowledged by the D and TPs, P is unlikely to be contributorily negligent. The parties may therefore wish to find an opportune moment (whether before or after the tri-partite expert report on liability is obtained) to consider mediation, or (if they had been to mediation and failed) to re-consider further mediation in the light of the updated litigation scene.