HKSAR v. WONG MAN YI MANDY

[English Translation]

CACC 267/2018

[2021] HKCA 182

IN THE HIGH COURT OF THE

HONG KONG SPECIAL ADMINISTRATIVE REGION

COURT OF APPEAL

CRIMINAL APPEAL NO 267 OF 2018

(ON APPEAL FROM HCCC NO 160 OF 2016)

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BETWEEN

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JUDGMENT

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Hon Yeung VP (giving the judgment of the Court):

Introduction

1.  The applicant (Wong Man Yi, Mandy) was charged with one count of trafficking in a dangerous drug, namely 3,987 grammes of a crystalline solid containing 3,868 grammes of “ice”. The applicant pleaded not guilty and was tried in the Court of First Instance before Wilson Chan J (“the trial judge”) and a jury.

2.  On 30 August 2018, the applicant was convicted by the jury and on the same day sentenced by the trial judge to 26 years and 8 months’ imprisonment.

3.  Feeling aggrieved at both the conviction and sentence, the applicant applied for leave to appeal against conviction and/or sentence. Subsequently, she abandoned her application in relation to sentence, which was accordingly dismissed on 26 June 2019.

4.  On 13 December 2019, a single Justice of Appeal ordered that the applicant’s leave to appeal against the conviction be determined by the full Court of Appeal and legal aid be granted to her.

5.  The applicant, represented by Mr Derek Chan SC, Mr Wong Hay Yiu and Ms Ferrida Chan, is asking this court for leave to appeal against her conviction.

Prosecution case and evidence

6.  At around 5:29 p.m. on 18 November 2015, the applicant was intercepted by Senior Customs Officer 9815 at the Green (Nothing to Declare) Channel in the Customs Arrival Hall at Lo Wu Control Point when entering Hong Kong from Shenzhen. The applicant was holding two transparent plastic bags, one containing a box of egg rolls and an almond biscuit box, and the other one containing three almond biscuit boxes. Inside the first almond biscuit box, there was a resealable plastic bag containing 997 grammes of a crystalline solid containing 968 grammes of “ice”. Each of the other three almond biscuit boxes contained a resealable plastic bag, in which there was altogether 2,990 grammes of a crystalline solid containing 2,900 grammes of “ice”. The market value of the “ice” in question at the time was about HK$1,180,000.

7.  Customs Officer 9788 arrested and cautioned the applicant, and made enquiries with her about the substance in one of the packets containing crystalline solids. The applicant said, “It is a dangerous drug, but I don’t know which kind. I helped a friend to collect it, a male friend called Ah Yin [transliteration]”. The applicant also told the customs officer that Ah Yin’s phone number was in her mobile phone, and indicated that the remaining crystalline solids were also the dangerous drugs given to her by Ah Yin, but she knew nothing whatsoever. It was Ah Yin who asked her to return the stuff to him after she went through the customs.

8.  The applicant signed in the customs officer’s notebook to confirm that its content was accurate and was voluntarily provided by her. Without noting any abnormality or loss of control on the part of the applicant, the customs officer stated that her mental condition was normal.

9.  Later on the same day, customs officers took the applicant to her residence for a search. After that she said she was physically unwell. The applicant’s mother requested that some medicines be given to the applicant, but the customs officers did not permit her to take medicines from an unknown source. In the end, at 12:25 a.m. on 19 November 2015, the customs officers took the applicant to the Accident and Emergency Department of Pamela Youde Nethersole Eastern Hospital for consultation. After making a diagnosis, Dr Chiang Shan Qing, Edward, a resident doctor of the Accident and Emergency Department, prescribed some psychotropic medication, which she took at 5:35 a.m. on the same day.

10.  In the video-recorded interviews conducted by customs officers on 19 November 2015, the applicant further admitted that she knew the substance that “Ah Yin” asked her to bring to Hong Kong was dangerous drugs, but she was not clear about the kind. The applicant also said that “Ah Yin” did not say anything about a reward, but did give her $2,000 “to pocket”.

11.  There is information showing that the applicant is a chronic mental patient. Dr Cheuk Tin Yan was the applicant’s attending doctor between 22 January 2014 and October 2017.

12.  According to Dr Cheuk’s testimony, the applicant was in a stable condition with no delusion or hallucination when she took over the applicant’s case. Dr Cheuk confirmed that two weeks prior to 31 December 2014, the applicant stopped taking a kind of antidepressant drug due to discomfort. Other than that, the applicant always attended follow-up consultations regularly and took medication on time.

13.  In March 2016, the applicant told Dr Cheuk for the first time that she had auditory hallucinations with a male voice telling her to die. In the subsequent follow-up consultations, the applicant made similar complaints time and time again. Nevertheless, Dr Cheuk stated that the applicant had no symptom of inability to distinguish imagination from reality and had no impaired memory or judgement. Her reasoning faculties were not compromised by her psychosis either.

14.  Dr Cheuk said no information showed that the applicant might be incapable of differentiating right from wrong on the day of the offence. Dr Cheuk also added that there was no sign that during the video-recorded interviews, the applicant did not understand the questions put to her by the customs officers, or that she displayed such symptoms as confusion, dullness, inability to concentrate, slow responsiveness or psychosis when answering questions.

The defence case and evidence

15.  The defence did not dispute the basic fact that the applicant was intercepted by a customs officer when she brought the dangerous drug into Hong Kong. However, it was argued that the applicant did not know the substance that “Ah Yin” asked her to bring to Hong Kong was a dangerous drug. The defence submitted that at the material time, the applicant was in a state of “insanity” and so she did not know what she was doing at the time or that what she was doing was wrong.

16.  When she gave testimony, the applicant said that she had been in the agony of depression for years with symptoms of hallucination and insanity, and even suicidal ideation. The applicant continued that both her parents also suffered from depression, while her elder brother was a person under disability with cerebral palsy and moderate mental retardation.

17.  The applicant claimed that on the material day when she attended the follow-up consultation, she did not tell Dr Cheuk that she had auditory hallucinations as she did not want to worry her mother, who was accompanying her. The applicant said that she started to have auditory hallucinations on the afternoon after she had attended the follow-up consultation, but she did not remember what she had heard. The applicant also said that she had felt confused and “involuntary” even though she did take medication prescribed by Dr Cheuk from the time of the follow-up consultation until her arrest.

18.  The applicant also spoke of her relationship with “Ah Yin”. She said that she came to know “Ah Yin” through her friend “Chicken Wing” between 2011 and 2012, but they were mere friends, not seeing each other very often. The applicant said that on the day in question, “Ah Yin” had asked her to bring some stuff to Hong Kong from the Mainland without telling her what it was.

19.  The applicant said that “Ah Yin” had previously made the same request to her but she did not agree. However, owing to the fact that “Ah Yin” bombarded her with repeated phone calls on that day, work pressure and health worries, she acceded to “Ah Yin’s” request.

20.  The applicant maintained that she could not recall what she did in Lo Wu after departing from home to there. She said she did ask “Ah Yin” about what stuff she was to deliver, but “Ah Yin” gave no reply. The applicant guessed she was to deliver cigarettes. The applicant further said that she only remembered she acted upon a customs officer’s instructions to put the two plastic bags through an X-ray machine for checking.

21.  The applicant also said that at the video-recorded interviews, customs officers told her that she would be released to see her mother if she admitted the offence early. She claimed that during the course of the interviews, her performance was sluggish and her responses were mechanical and involuntary. According to the applicant, she was mentally confused and had auditory hallucinations, even not knowing what she was doing.

22.  The defence also called Dr Nip Wai to testify on the applicant’s mental condition. Dr Nip was the attending psychiatrist of the applicant between July 2009 and December 2013. After the incident took place, Dr Nip interviewed the applicant on two occasions, 15 and 26 June 2017, for a total of 8 hours. Before testifying, Dr Nip viewed the applicant’s video-recorded interviews taken by the customs officers and made reference to the applicant’s medical records.

23.  Dr Nip opined that during the interviews with the customs officers, the applicant displayed dullness, eye-fixation problem, and signs of inappropriate affect, signs of wandering off topics, circumstantial speech, illogical judgement and involuntariness. Dr Nip took the view that the applicant might be incapable of weighing the pros and cons of a matter and was very likely unable to determine what was right or wrong, morally and legally.

24.  Nevertheless, Dr Nip admitted that he could not determine the veracity of the applicant’s account in relation to her physical condition. He gave his opinion on the basis that the applicant had told the truth.

25.  Dr Nip said that the first time he had heard the account that suddenly the defendant’s mind was “a complete blank” when she spoke to “Yin Jai” on the phone and that the condition persisted until after she had returned to Hong Kong via Lo Wu was when the applicant testified as to this in court. Dr Nip opined that as the applicant’s assertion was not supported by medical evidence, he had reservations about it.

Trial judge’s direction to the jury

26.  In respect of the defence case advanced by the applicant, the trial judge first pointed out to the jury that:

“…The defendant’s case is that she had no knowledge whatsoever of the dangerous drug contained in the almond biscuit boxes. Moreover, her mind was a complete blank at that time, and she did not know what she was doing was wrong…”

“In respect of the elements of the offence in the present case, including the defendant’s knowledge that the substance involved was a dangerous drug, if you are of the view that there is a reasonable doubt, or if you cannot be sure that the defendant definitely committed the offence, you must return a verdict of not guilty…”

“…There are two matters that the prosecution must prove. Firstly, the defendant imported the dangerous drug in question into Hong Kong, that is, she brought the dangerous drug into Hong Kong by land. Secondly, the defendant knew that the substance involved was a dangerous drug, that is, the defendant knew that the almond biscuit boxes contained a dangerous drug…”

“…The prosecution must prove that the defendant knew the substance was a dangerous drug, and it will not be sufficient to only prove that the defendant knew the substance concealed was contraband. The prosecution must prove that the defendant knew the substance concealed was a narcotic or a dangerous drug…. If you cannot be sure the prosecution has proven all the elements of the offence of trafficking in a dangerous drug, including the defendant’s knowledge that the substance in question was a dangerous drug, you must return a verdict of not guilty. If you are sure that the prosecution has proven all the elements of the offence, you must return a verdict of guilty.”

27.  As to the applicant’s defence of “insanity”, the trial judge directed the jury as follows:

“Apart from that, however, in the present case, the defendant put forward a defence on the ground of insanity. The defendant’s case is that at the time of committing the act, namely, when she brought the dangerous drug into Hong Kong, she was labouring under such a defect of reason, from a disease of the mind, as not to know at all the nature and quality of the act she was doing; or if she did know it, that she did not know what she was doing was wrong. As Mr Yuen of counsel mentioned yesterday, everyone is presumed in law to be sane with sufficient faculties of reason to be held responsible for the crime one has committed, until the contrary is proved to your satisfaction. Moreover, for a defence of insanity to be established, it must be clearly proved that at the time of committing the act, the defendant was labouring under such a defect of reason, from a disease of the mind, as not to know the nature and quality of the act she was doing; or if she did know it, that she did not know what she was doing was wrong. In other words, under the law, it is for the defendant to prove that she is entitled to be given a special verdict of not guilty by reason of insanity. In this regard, unlike the duty required of the prosecution, the defendant does not have to make you sure about her insanity. However, she must establish this point to your satisfaction on a balance of probabilities. In other words, she must prove by evidence that when she brought the dangerous drug in question into Hong Kong, she was labouring under such a defect of reason, from a disease of the mind, as not to know the nature and quality of the act she was doing; or if she did know it, that she did not know at all what she was doing was wrong. The defence must prove the three constituents I mentioned above, namely disease of the mind, the resulting defect of reason, and the third being that she did not know the nature and quality of the act she was doing; or if she did know it, that she did not know what she was doing was wrong. Only with these three constituents proved can the defence of insanity be established; all three constituents are indispensable.

You should deal with all these questions by adopting a broad common-sense approach. If the defence fails to prove any one or more of these constituents whereas the prosecution can prove the aforesaid elements of the offence of trafficking in a dangerous drug, you must return a verdict of guilty of trafficking in a dangerous drug. However, if the defence satisfies you, on a balance of probabilities, that the three constituents of the insanity defence were all present at the time when the defendant brought the dangerous drug into Hong Kong, you must return a verdict of not guilty by reason of insanity, namely a special verdict of not guilty by reason of insanity under section 74 of the Criminal Procedure Ordinance, as mentioned by Mr Lee of counsel yesterday.”

“Apart from that, however, the defendant put forward a defence on the ground of insanity in the present case. The defendant’s case is that at the time of committing the act, namely when she brought the dangerous drug into Hong Kong, she was labouring under such a defect of reason, from a disease of the mind, as not to know at all the nature and quality of the act she was doing; or if she did know it, that she did not know what she was doing was wrong. As far as this defence goes, the burden of proof is on the defendant. In other words, under the law, it is for the defendant to prove that she is entitled to be given a verdict of not guilty by reason of insanity. The defendant does not have to make you sure about her insanity, but she must establish this point to your satisfaction on a balance of probabilities. That is, she must prove by evidence that when she brought the dangerous drug in question into Hong Kong, she was labouring under such a defect of reason, from disease of the mind, as not to know at all the nature and quality of the act she was doing; or if she did know it, that she did not know what she was doing was wrong.” (emphasis added)

28.  The trial judge recapitulated to the jury in detail the medical opinions presented by both parties, especially the testimonies of Dr Cheuk and Dr Nip, on the applicant’s medical condition. The trial judge also recounted the testimonies given by the customs officers who handled the applicant at the time of the offence to help the jury understand her state of mind at the material times and determine whether she could rely on the defence of “insanity”.

29.  In relation to the applicant’s confessions alleged by the prosecution, the trial judge told the jury the following:

“The prosecution relied on such confessions and further alleged that the facts admitted by the defendant are all true. When considering whether it is safe and satisfactory to rely on the facts admitted by the defendant as the basis for determination, you must take into account two points: first, in the verbal cautioned statement and the post-recorded cautioned statement, whether the defendant did in fact make such confessions. Hence, the first question is, you need to make a finding of fact as to whether the defendant did in fact make such confessions. If you are not sure she did, you will not have regard to such confessions. However, if you are sure she did make such confessions, you will have to ask the second question, which applies to the verbal cautioned statement, post-recorded statement, and the video-recorded interviews. The question is whether you are sure about the truth of such confessions. When considering this question, you must decide whether the defendant’s confessions were or might have been obtained by oppression or whether some words had been said or some acts done by someone which might render her confessions unreliable. If you conclude that the facts admitted by the defendant or the answers provided by her were or might have been a result of the oppression exerted by people from the Customs and Excise Department, or due to some words said or acts done, which might render the defendant’s confessions unreliable, you will not have regard to such confessions of the defendant either.

In this case, the defendant alleged that after her arrest, she was disturbed by mental illness and denied medication by the customs officers. As alleged by the defendant, before both the first and second video-recorded interviews, customs officers had told her that if she admitted the offence early, she would be released on recognizance or bail to see her mother. This is the defendant’s allegation. If you conclude that the defendant’s allegations are true or may be true and that her confessions were or might have been a result of such acts, you must put those confessions out of your mind, and not rely on them as the basis of your verdict.

However, if you are sure that the defendant did in fact make those confessions and that the above circumstances as alleged by the defendant did not happen, you must still consider whether you are sure about the truth of such confessions. If, for whatever reason, you are not sure that such confessions are true, you must disregard them. If you are sure that the facts confessed by the defendant are true, you can rely on them as the basis of your verdict.” (emphasis added)

Grounds of appeal

30.  Mr Derek Chan SC, counsel for the applicant, advanced various grounds of appeal, largely involving the issue of whether the applicant was affected by “insanity” at the time of the offence and after the arrest.

31.  In respect of the defence of “insanity”, Mr Chan SC criticised the trial judge for erroneously placing a persuasive burden on the applicant. He submitted that the applicant had already satisfied her evidential burden by bringing up the fact that she was affected by “insanity”. Thus, the applicant should only be convicted if the prosecution could disprove beyond reasonable doubt the defence of “insanity” raised by the applicant.

32.  Mr Chan SC also argued that the trial judge gave the jury inadequate directions on the issues of the applicant’s confessions and her knowledge of the dangerous drug she delivered.

33.  Mr Chan SC stressed that the burden rests on the prosecution to prove beyond reasonable doubt that the applicant had made the confessions and that her confessions were reliable. Regarding this issue, he added that the prosecution must disprove the possibility that the applicant’s mental illness would affect her making of the confessions and that her confessions were unreliable. It was strenuously argued that the trial judge had failed to give the jury adequate directions on the fact that the applicant was being affected by mental illness when she was interviewed by the customs officers, and the trial judge did not even direct the jury to exercise great caution if they were to rely on the applicant’s confessions to convict her. And the jury was not reminded that they must exclude the applicant’s confessions from evidence if such confessions were or might have been affected by her mental illness and became unreliable.

34.  Mr Chan SC argued that the trial judge should direct the jury that, when determining whether she knew at the material time that the substance she delivered was a dangerous drug, even if they rejected the defence of “insanity”, they should still consider whether the applicant’s mental illness at that time would affect her knowledge of the nature of the substance she delivered.

35.  Lastly, Mr Chan SC submitted that the trial judge had unduly interfered with the defence expert witness’ testimony, and that had deprived the applicant of a fair trial. In his opinion, the trial judge assumed the role of a “prosecutor” and descended into the “arena”, which caused a reasonable and informed bystander to have the impression that the applicant had not been given the chance of a fair trial.

Discussion

36.  Mr Chan SC agreed that everyone is legally presumed to be sane and to possess a sufficient degree of reason to be responsible for his crimes (“presumption of sanity”). He also agreed that currently in common law, if a defendant in a criminal case seeks to rely on the defence of “insanity” under the M’Naghten Rules (namely, (1) the defendant did not know the nature and quality of the act he was doing; that is, he did not know what he was doing; or (2) if he did know it, he did not know what he was doing was wrong), he must rebut the “presumption of sanity”. To rebut the presumption, a defendant bears not only the evidential burden but also the persuasive burden to prove on the balance of probabilities that he was affected by his “insanity” at the material time so that he was not responsible for his criminal act.

37.  As a matter of fact, Woolmington v DPP [1935] AC 462 laid down the common law principle that in criminal prosecutions, the onus is certainly on the prosecution to prove the guilt of the defendant. However, when Viscount Sankey LC first referred to M’Naghten’s case in his judgment, he made it clear that, “In M’Naghten’s case, the onus is definitely and exceptionally placed upon the accused to establish such a defence.” He specified (at page 481) that the defence of “insanity” was an exception: “Throughout the web of the English Criminal Law one golden thread is always to be seen, that it is the duty of the prosecution to prove the prisoner’s guilt subject to what I have already said as to the defence of insanity and subject also to any statutory exception.”

38.  In R v Sullivan [1983] 2 All ER 673, the M’Naghten Rules were explained clearly by the House of Lords, constituted by such eminent judges as Lord Diplock, Lord Scarman, Lord Lowry and Lord Brandon:

“When a defence of insanity was put forward on a criminal charge it remained the case that the accused had clearly to prove, in accordance with the definition of insanity in the M’Naghten Rules, that at the time of committing the criminal act he was labouring under a ‘defect of reason’ resulting from ‘disease of the mind’, the term ‘mind’ being used in the ordinary sense of the mental faculties of reason, memory and understanding. Thus, if the effect of a disease was to impair those faculties so severely as to have the consequence that the accused did not know what he was doing, or, if he did, that he did not know that it was wrong, he was ‘insane’ in the legal sense.”

39.  The views of Lord Diplock in Sullivan were also affirmed in R v Hennessy [1989] 2 All ER 9.

40.  It was decided by the European Court of Human Rights in H v the United Kingdom (Application No. 15023/89 European Court of Human Rights) that the rule of placing the burden upon the accused to prove the defence of “insanity” is not contrary to the “presumption of innocence” ensured by Article 6.2 of the European Convention on Human Rights, for it does not concern the “presumption of innocence” but the “presumption of sanity”.

41.  In R v Smith (Oliver) (1911) 6 Cr App R 19, the Lord Chief Justice likewise reiterated that:

“The only general rule that could be laid down was that insanity, if relied upon as a defence, must be established by the defendant.”

42.  In Sodeman v R [1936] 2 All ER 1138, Viscount Hailsham LC reiterated at page 1140 of his judgment that: “… but it is certainly plain that the burden in cases in which an accused has to prove insanity may fairly be stated as not being higher than the burden which rests upon a plaintiff or defendant in civil proceedings.”

43.  As fairly pointed out by Mr Chan SC, Hong Kong courts have all along followed the above common law principle by imposing a “persuasive burden” on a defendant who relies upon the “insanity” defence (see e.g., Lam Kwong Choi v R [1959] 2 HKLR 252; HKSAR v Wong Hung Fai, Joseph, unreported CACC 153/2007).

44.  When the Court of Final Appeal discussed the “presumption of innocence” under the Basic Law of Hong Kong and the Hong Kong Bill of Rights Ordinance in HKSAR v Ng Po On (2008) 11 HKCFAR 91, the Court observed that the placing of burden on the defendant to establish a “reasonable excuse” under section 24 of the Prevention of Bribery Ordinance, Cap. 201 infringes the “presumption of innocence”, but it made clear that it did not intend to discuss whether the “insanity” defence was an exception. The Court of Final Appeal also referred to HKSAR v Lam Kwong Wai & Another (2006) 9 HKCFAR 574 where Sir Anthony NPJ discussed the significance of the “presumption of innocence” at common law, and confirmed that the “insanity” defence is an exception to the burden of proof placed on the prosecution. Ng Po On does not support the stance of Mr Chan SC.

45.  With no precedent whatsoever to rely upon, Mr Chan SC still hopes to convince us that the reverse onus applicable to “insanity” violates the principle of “presumption of innocence”, constituting a disproportionate derogation from the defendant’s right of presumed innocence under Article 87 of the Basic Law and Article 11(1) of the Hong Kong Bill of Rights Ordinance.

46.  Mr Chan SC draws on various literature in support of his stance, including authorities from jurisdictions such as England, the United States and Canada; a discussion paper from the English Law Commission; the learned opinions of the editors of some legal textbooks; and the dicta in a number of cases.

47.  It was vehemently argued by Mr Chan SC that where the “insanity” defence arises, a “reverse onus” (ie a “persuasive burden”) on the defendant will derogate from the defendant’s right of presumed innocence and fail to satisfy the proportionality test.

48.  In the opinion of Mr Chan SC, when a defendant raises the “insanity” defence, a mere evidential burden on him would suffice to resolve the following problems, namely: (i) preventing a sane defendant from evading criminal liability by abusing the insanity defence; and (ii) since it would be too onerous a burden for the prosecution to prove the defendant’s sanity beyond reasonable doubt and only the defendant himself knew the facts constituting his defence, the “persuasive burden” should be reversed.

49.  As strenuously submitted by Mr Chan SC, after the defendant has discharged an evidential burden, the prosecution should bear a “persuasive burden” to negate the “insanity” defence. Mr Chan SC also emphasised that, even if the defendant succeeds in relying upon “insanity” as a defence, a special verdict returned by the jury would on most occasions result in a hospital order to be imposed on the defendant. Therefore, the “insanity” defence would not be open to abuse.

50.  It must first be noted that the task of Mr Chan SC is a formidable, exceptionally challenging and even insurmountable one because he is virtually asking us to reject a vast number of precedents across common law jurisdictions and the previous decisions of this court. Some of the literature submitted by Mr Chan SC, albeit in line with his stance, is nonetheless based on certain special circumstances. To date, the courts in common law jurisdictions such as England, Australia, Canada and New Zealand have yet to rule in favour of imposing a mere “evidential burden” on the defendant in respect of the “insanity” defence, and a “persuasive burden” on the prosecution to negate that defence beyond reasonable doubt.

51.  We are not in a position to overrule the previous decisions of this Court of Appeal, nor do we have any ground to depart from the many cases of the other common law jurisdictions. In fact, the defence counsel at trial did not ask the trial judge to deal with the case according to the stance put forward before us by Mr Chan SC.

52.  In any event, we are of the view that, on the premise that everyone is presumed to be sane with sufficient faculties of reason to be held responsible for the crime he has committed, it is reasonable to impose not only an evidential burden but also a persuasive burden on the party who wishes to rebut the presumption of “sanity” with the “insanity” defence and this also meets the tested societal consensus.

53.  We agree with the observations of Mr Ira Lui, Assistant Director of Public Prosecutions representing the respondent. At common law, while it might undermine the presumption of innocence by “reversing the burden of proof” and imposing a persuasive burden on a defendant who relies on “insanity”, the purpose is to avoid exonerating the guilty too easily. This is a reasonable restriction on the right protected by the presumption of innocence and fully satisfies the rationality test.

54.  In Chaulk and Another v R [1991] LRC (Crim) 485 cited by Mr Chan SC, the Supreme Court of Canada specifically examined the defence of insanity, and held that the reversal of the onus of proof for “insanity” is a reasonable restriction on the right protected by the presumption of innocence.

55.  Mr Chan SC invites this court to follow the dissenting opinion of Wilson J instead of the majority view in the case above. Mr Chan SC’s submission is not convincing. We disagree.

56.  In our view, the decision on a similar issue by the English Court of Appeal in R v Foye (2013) 177 J.P. 499 is highly instructive and should be followed. The defendant in Foye was charged with murder. At the trial, he agreed that he had killed the deceased but raised the defence of “diminished responsibility”. The defendant was convicted and later he lodged an appeal. One of his grounds of appeal was that it was a violation of the right to presumption of innocence under Article 6.2 of the European Convention on Human Rights to “require the defendant to prove on the balance of probabilities that he was suffering from an abnormality of mind at the time of the offence”. That Article was incorporated into English domestic law by the Human Rights Act 1998 of the United Kingdom.

57.  The English Court of Appeal found that the imposition of a persuasive burden on a defendant for the defence of “diminished responsibility” satisfies the proportionality test. As pointed out by the English Court of Appeal, the position is the same for the defences of “insanity” and “diminished responsibility”. It is entirely reasonable for the law to require a defendant to prove a matter so personal to him, and no prejudice is caused to any of his rights and interests. Paragraph 33 of the judgment states the following:

“The law does not in any way inhibit a defendant from demonstrating that in his case this ordinary assumption (of sane) cannot be made, but it is entirely reasonable that a matter so personal to the defendant should be for him to prove, albeit only on the balance of probabilities. For the same reason, the position is identical if the defendant asserts not diminished responsibility but the greater mental disability of insanity in law: that is likewise for him to prove on the balance of probabilities.”

58.  The English Court of Appeal further stated in paragraph 35 of the judgment that:

“In the case of both insanity and diminished responsibility, the issue depends on the inner workings of the defendant’s mind at the time of the offence. It would be a practical impossibility in many cases for the Crown to disprove (beyond reasonable doubt) an assertion that he was insane or suffering from diminished responsibility. Of course, if there were a bare assertion, or one supported only by poor evidence, it would be open to the Crown to invite the jury to reject it, but, if the onus lies on the Crown to disprove the condition beyond reasonable doubt, this would not be enough. It would have to adduce evidence of the absence of abnormality in the defendant’s mental state. But the defendant is under no obligation to submit to a medical examination and may well refuse. If he does formally submit, he may simply fail to co-operate. He may refuse, lawfully, to make available past medical or other records which are necessary to a report on his condition. This is a simple but fundamental reason why the reverse onus is essential to the working of the law of diminished responsibility.”

59.  In DPP v Heffernan [2017] 1 IR 82, one of the cases cited by Mr Chan SC, the Supreme Court of Ireland also concurred with the analyses and conclusions of Chaulk and Foye, and held that the imposition of a “reverse burden of proof” on the defendant satisfies the proportionality test, whether he raises the defence of “insanity” or “diminished responsibility”.

60.  We agree on the approach in the above cases.

61.  In dealing with the defence of “insanity” raised by the applicant, the trial judge pointed out to the jury that the applicant bore the burden of proving the defence on the balance of probabilities. The way the trial judge dealt with the issue was compliant with the legal requirements, and was correct.

62.  In a jury trial, the trial judge must act impartially. He must not make a reasonable bystander think that he is biased towards any side, nor should he evince any hostility towards any side’s witnesses. The trial judge should, as far as possible, allow the prosecution and the defence to present their respective cases by conducting examination-in-chief, cross-examination and re-examination. Excessive interference should be avoided, lest it give rise to an impression that the judge has a predetermined view, affecting the jury in reaching a fair verdict.

63.  Apart from explaining the legal issues to the jury, the trial judge must also direct the jury properly on the facts of the case. In order to discharge this duty properly, the trial judge must have a thorough understanding of the testimonies of the witnesses.

64.  The questioning of the witnesses by the prosecution and the defence may not necessarily enable the trial judge to have a full grasp of their testimonies so as to properly direct the jury.

65.  Under such circumstances, it is absolutely necessary and appropriate for the trial judge to ask the witnesses questions. This does not mean that the trial judge has entered the “arena”, nor does this mean that the defendant has been deprived of a fair trial.

66.  Certainly, whether the trial judge’s questioning constitutes a prima facie case of bias will depend on the particular circumstances of each case. The number of questions alone is not decisive. What one needs to consider are the quality and quantity of the questions, and how these two factors react upon each other. (See R v Yeung Mau Lam [1991] 2 HKLR 468)

67.  We should first point out that the applicant’s account is highly unusual, ambiguous, and very hard to follow. She stated that on the material day when she went to Lo Wu after midday, she acted involuntarily, was confused, and had auditory hallucinations, failed memory and a completely blank mind.

68.  When asked by her counsel if she remembered where she had been and what she had done subsequently, the applicant replied, “Cannot really remember. Now, I can’t recall.”

69.  The applicant further said that she was not even sure what she had answered. However, she remembered the circumstances of how “Ah Yin” handed her the stuff. She also recalled that the two bags of stuff were placed on the conveyor belt by the Customs officer. She went on to say that she had some recollection of the incident.

70.  On the one hand, the applicant claimed that she had no idea what she had done or was doing at all. Yet, on the other hand, she alleged that she did ask “Ah Yin” and was informed that she was to deliver cigarettes.

71.  The applicant repeatedly said that during her stay on the Mainland, she had a blank memory and “did not quite know what I was doing after leaving home”. On the above issue, the applicant simply contradicted herself during examination-in-chief, cross-examination, and re-examination.

72.  We cannot ignore the testimony of Dr Nip, who was called by the applicant. Dr Nip also testified that he heard from the applicant that her mind at the time of the offence was “a complete blank” with no recollection of anything for the first time in court.

73.  The trial judge could have waited until the counsel for both sides had finished their questions before asking the applicant to clarify the obscurities in her testimony, but that might not have been the best course of action in the circumstances of this case. By raising questions on the spot to clarify the issues with the applicant, the trial judge could not only immediately draw the jury’s attention to his concerns but also help the jury understand the applicant’s testimony. This also avoided belated questions which would have made the applicant’s testimony even harder to understand. The approach taken by the trial judge was reasonable and appropriate.

74.  This court has carefully considered the questions put to the applicant by the trial judge when she testified. We are of the view that the trial judge’s questions to the applicant raised on the spot to clarify her inconsistencies were certainly not unfair to her. In the circumstances of this case, it was not only appropriate but also a preferable approach.

75.  We disagree that the trial judge misled the jury by imposing his own interpretation of the phrase “a complete blank” on the applicant.

76.  We agree with the observations of Mr Ira Lui. By clarifying the applicant’s testimony in a timely manner, the trial judge not only ensured that the questions asked by the parties were specific and fair, but also ensured that his summing-up of the testimonies to the jury was more detailed and accurate. In fact, the transcript demonstrates the extreme care given to the detail by the trial judge in recording the testimonies and his immediate corrections whenever the prosecution’s questions were inaccurate. The purpose was to safeguard the applicant’s interests. Similarly, when Dr Nip explained his observations in relation to the applicant’s behaviour in the video-recorded interviews, the trial judge also asked him questions for the purpose of clarifying Dr Nip’s testimony so that the jury could immediately understand his testimony.

77.  This court finds that the trial judge’s timely clarification with the witnesses on the ambiguities of their testimonies was an appropriate course of action. The trial judge also gave the defence ample opportunity to address the issues arising from his questioning of the witnesses.

78.  Given the background of the case and the nature of the testimonies from the applicant and Dr Nip, we are of the view that the trial judge’s questioning would in no way lead a reasonable and informed bystander to perceive that the trial judge was biased towards any party or hostile to the defence witnesses.

79.  The contention of Mr Chan SC that the trial judge had lost his neutrality by entering the “arena” with apparent bias is untenable.

80.  The relevant issues in this case certainly include whether the applicant knew the substance she brought into Hong Kong was a dangerous drug, and whether the jury could properly rely on the applicant’s confessions as proof.

81.  Concerning the applicant’s knowledge of the dangerous drug in question, the trial judge went straight to remind the jury that the applicant’s case was that she had no knowledge whatsoever that the almond biscuit boxes contained a dangerous drug, and that her mind went completely blank at the time, not knowing what she herself was doing. The trial judge clearly stated the following to the jury:

“In respect of the elements of the offence in the present case, including the defendant’s knowledge that the substance involved was a dangerous drug, if you are of the view that there is a reasonable doubt, or if you cannot be sure the defendant definitely committed the offence, you must return a verdict of not guilty.”

82.  The trial judge also gave detailed directions to the jury on the applicant’s confessions. (See paragraph 29 above)

83.  Mr Chan SC complained that the trial judge failed to adequately direct the jury on the issues of the applicant’s knowledge of the nature of the dangerous drug involved, whether the applicant had confessed, and whether the contents of her confessions were true. In particular, the trial judge failed to explain to the jury the interplay between the applicant’s mental condition and these issues.

84.  At trial, the applicant’s stance was clear. She said that she had auditory hallucinations, confusion and “involuntariness” when the offence occurred, and that she was having mental confusion, auditory hallucinations, and did not know what she was doing during her video-recorded interviews with the customs officers. In fact, most of the time in the trial was spent on dealing with the applicant’s mental condition at the relevant times. The trial judge’s directions to the jury were also devoted at great length to addressing the same issue.

85.  However, the trial judge’s directions to the jury on the applicant’s mental condition at the material times focused only on her defence of “insanity”. The trial judge did not adequately deal with the interplay between the applicant’s mental condition and the issues of whether she knew that the substance was a “dangerous drug” at the time of the offence, whether she made the confessions voluntarily and whether the contents of those confessions were true and accurate.

86.  We note that when directing they jury on the defence of “insanity”, the trial judge closely followed the relevant Specimen Directions. However, we would stress that when a trial judge gives directions to the jury, his approach should not be rigidly set in stone. Proper adjustments need to be made according to different circumstances of individual cases.

87.  In the present case, the applicant’s mental condition at the material times did not only concern her defence of “insanity”, but also other issues, including whether she knew at that time that the substance she brought into Hong Kong was a dangerous drug, whether she made the confessions, and whether the contents of her confessions were true.

88.  We cannot disregard the undisputed evidence that the applicant suffered from mental illness with such symptoms as depression and auditory hallucinations; and that the applicant had been receiving treatment from a psychiatrist since 2009. At the material time, she was still under psychiatric treatment and on psychotropic medication. Her mental condition might make her more gullible and easily believe in people. It might also cause her to be more susceptible to the influence of the customs officers and to making confessions which she should not have made or confessions that might be untrue.

89.  Therefore, when the jury considered whether the applicant knew the substance she brought into Hong Kong was a “dangerous drug” at that time, whether she had confessed, and whether the contents of her confessions were true, the jury must take her mental condition into account even if they did not accept her defence of “insanity”.

90.  A stringent test on this issue would be to assume that the applicant did not raise the defence of “insanity” but there was information showing that she was indeed mentally ill. How should the trial judge direct the jury? Should the trial judge direct the jury to take the mental condition of the applicant into account when considering whether she knew the nature of the substance she brought into Hong Kong, whether she had confessed, and whether the contents of her confessions were true? The answer is plain and obvious.

91.  In HKSAR v Chen Xuehui (CACC 394/2012), the defendant suffered from bipolar disorder. On whether the defendant knew the suitcase she brought into Hong Kong contained a dangerous drug, the trial judge told the jury that:

“Mr Khosa, unsurprisingly, relies upon the evidence of Dr Choi, DW3. Dr Choi’s evidence was that the defendant was a sufferer of a mental illness known as bipolar disorder. When she was having an episode of this disorder, she would display symptoms which would make her more susceptible to believing in other people and that she would have defective judgment and would be more easily misled. In other words, you might think, members of the jury, that a person suffering from this illness, when the illness was affecting them, could be prone to arriving honestly at an understanding of events that normal people such as yourselves would not arrive at; they might be more easily duped.”

“Let me emphasise this: If the defendant’s mental condition simply encouraged her to knowingly bring these drugs into Hong Kong, that does not help her case; she still brought the drugs knowingly into Hong Kong. But if the defendant’s mental condition, you think, may have made her wrongly believe that there were no drugs in that suitcase, may have allowed her to be more gullible and more easily convinced that the suitcase had no drugs, if you think her condition may have encouraged her to believe there were no drugs in the suitcase, that of course goes to her state of knowledge and that, of course, does mean that you cannot convict her. …”

92.  The above approach has been approved by the Court of Appeal as correct.

93.  In the present case, when directing the jury on the elements of the offence, including whether the applicant knew the substance she brought into Hong Kong was a dangerous drug, the trial judge made no reference to the applicant’s mental condition at the time of the offence. When directing the jury on the applicant’s confessions, the trial judge did mention that the applicant was disturbed by mental illness but customs officers did not let her take medicine. All the trial judge emphasised was the customs officers’ refusal to let her take medicine. He did not ask the jury to consider if the applicant’s mental condition may have had an impact on whether she made the confessions at all and, if so, whether the contents of her confessions were true.

94.  We should point out that when directing the jury on the applicant’s mental condition, the trial judge focused only on whether her defence of “insanity” was established. After the jury decided that the defence was not established, it was highly likely that they then put aside the applicant’s mental condition; when analysing such issues as whether the applicant knew the nature of the substance she brought into Hong Kong, whether she had confessed, and whether the contents of her confessions were true, the jury might have not taken her mental condition into consideration.

95.  At the hearing, Mr Chan, SC, made a submission on the sequence of addressing how the applicant’s mental condition would affect her knowledge of the dangerous drug, the nature of her confessions and whether the defence of “insanity” was established.

96.  We are of the view that the key is not the sequence of the directions, but the need for the trial judge to remind the jury that even if they rejected the applicant’s defence of “insanity”, they must still take her mental condition into account when considering whether she knew the substance she brought into Hong Kong was a dangerous drug, whether she had confessed, and whether the contents of her confessions were true.

97.  When the offence happened, the applicant suffered from mental illness, which might affect her knowledge of the nature of the dangerous drug involved. It may also be relevant to the questions of whether she had confessed, and whether the contents of her confessions were true. It is irregular for the trial judge to fail to deal with those issues properly when directing the jury. Hence, the conviction of the applicant was rendered unsafe.

Conclusion

98.  Under such circumstances, this court grants the applicant leave to appeal against conviction. The appeal is allowed. The conviction is quashed and the sentence set aside.

99.  This court also orders that further applications, if any, must be made within 14 days after this judgment is handed down. Further directions will be given on the application. During the period, the applicant must be remanded in custody pending the court’s directions.

Translation vetted by Ms. Jenny Chung, Solicitor.