HKSAR v. VALENCIA BERNIE MACATANGAY

HCCC 226/2023

[2025] HKCFI 2840

IN THE HIGH COURT OF THE

HONG KONG SPECIAL ADMINISTRATIVE REGION

COURT OF FIRST INSTANCE

CRIMINAL CASE NO. 226 OF 2023

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REASONS FOR DECISION:

EXPERT EVIDENCE

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Introduction

1.  The prosecution sought to introduce the evidence of two experts, namely Dr. Ying Ho-wan (a forensic pathologist) and Dr. Pang Ka-hung Peter (a specialist in neurosurgery), as part of the prosecution’s case against the Accused for the murder charge.

2.  Counsel for the Accused, Mr. Arthur, accepted that given he was a highly qualified neurosurgeon, Dr. Pang was quite entitled to describe the brain injuries that he observed on the deceased, and to conclude that they were blunt impact injuries and that the cause of death was traumatic head injuries with intracerebral haemorrhage and brain damage. But Mr. Arthur contended that Dr. Pang was not able to go further and give the opinion that the head injuries were non-accidental rather than accidental and were caused by fists or kicking.

3.  Mr. Arthur opposed certain parts of the evidence contained in the “Expert Witness Report” dated 24 January 2024 of Dr. Pang. In particular, it was contended that Dr. Pang had no qualifications which permitted him to express opinions in his “Expert Witness Report” on the following matters: (1) the pattern, distribution and severity of injuries over the deceased’s body were inconsistent with accidental causes due to falls and subsequent head injuries (§1.3a); (2) the pattern of multiple and bilateral involvement in the body injuries spoke against accidental causes but hinted at the likelihood of non-accidental injuries (§1.3c); (3) bilateral facial bruises and swellings were due to blunt injuries that could be resulted from direct blows to the face, i.e. by bare hands (§1.3d); (4) the bruising and swelling over the deceased’s limbs could have represented defensive injuries during the alleged assault (§1.3e); (5) diffuse axonal injury (DAI) is a type of brain injury caused by rapid acceleration or deceleration forces and is characterized by widespread damage to the brain’s white matter or neuron fibres; it is more commonly associated with non-accidental trauma with the component of severe shaking or rotational forces in the abuse (§4.3); (6) the cause of the deceased’s fatal head injuries was non-accidental and alleged assault with the use of blunt objects, i.e. fisting with bare hands or kicking with feet, was the likely mechanism of inflictions (§5.1) — these matters are collectively referred to as the “disputed matters”. Mr. Arthur contended that these disputed matters were within the realm of forensic pathology and outside the expertise of Dr. Pang.

4.  Mr. Arthur contended that as a specialist in neurosurgery, Dr. Pang’s expertise was limited in that field only and he was not qualified to give expert evidence on the disputed matters.

5.  In order to determine whether Dr. Pang had expertise in such disputed matters, a voir dire was held on 31 March 2025 during which he gave evidence and testified at some lengths as to the training he had received, his past practice at different hospitals and medical centres, and the extent and breadth of his accumulated clinical experience and knowledge. It was the prosecution’s submission that by virtue of all of that exposure, experience and knowledge, Dr. Pang was sufficiently qualified to give an opinion on the disputed matters.

Dr. Pang’s evidence during the voir dire

6.  I will not repeat at lengths the evidence that Dr. Pang gave during the voir dire but will adopt the following summary of his evidence as set out by the prosecution in its written submissions, which I found and Mr. Arthur accepted to be accurate:-

“5. In 1992, Dr. Pang obtained his undergraduate degree of Bachelor of Medicine and Bachelor of Surgery at the University of Hong Kong. In his first two years, being taught by qualified professors (who were practitioners in the relevant fields) he had already acquired medical knowledge on all kinds of trauma, including head trauma. He also had the chance to dissect bodies and learn about the human anatomy to deepen his understanding. In the next three years, he was also regularly having practice sessions at hospitals to gain first-hand experience.

6. In his sixth year, it was a full-time internship with rotations at different hospitals to fully put his skills and knowledge to use. For the first six months, Dr. Pang was attached to the General Surgery unit at the Queen Mary Hospital, where he was exposed to different patients with all types of trauma, including head trauma, body trauma and multiple trauma. He was exposed to cases such as road traffic accident, falling from height and sports injury.

7. Subsequently, Dr. Pang spent two years in the General Surgery Unit of other two hospitals, before moving to the Accident and Emergency Unit of Kwong Wah Hospital. There, given the nature of the A&E Unit, Dr. Pang was the first person to receive and diagnose patients who were rushed to hospital. The experience was thus especially extensive, where Dr. Pang was exposed to a vast array of trauma cases caused by different types of events, such as domestic falling and assault with blunt objects. Dr. Pang was able to gain clinical experience to distinguish brain injuries and head trauma that were accidental from those that were non-accidental.

8. Dr. Pang especially recalled that the case load was extremely high at the A&E Unit back then, where each doctor took on over 100 cases per day (including cases of industrial accident, fall from height and assault). Dr. Pang also recalled that Kwong Wah Hospital was near Mong Kok where there used to be numerous patients being sent to hospital following gang fights. He was thus very familiar with assault cases, and cases involving ‘defensive injuries’ i.e. the injuries sustained when one is trying to protect himself from his assailant, usually by raising his arms to brace his head.

9. Since 1997, Dr. Pang had then specialised in neurosurgery, further enhancing his skills, knowledge and experience in diagnosing and treatment brain injuries and head trauma. While not as intensive as the A&E Unit, Dr. Pang had still been seeing 10 to 30 patients a day at Neurosurgery, with most of them sustaining head injuries. Over the years, Dr. Pang had seen many cases[1], from minor concussion to very severe cases.

10. Despite the specialisation in neurosurgery, Dr. Pang would not only focus on a patient’s head injuries. In order to make a preliminary diagnosis, Dr. Pang would have to consider all clinical signs available from the patient, including wounds, scars and bruises in other areas of the body in addition to the head. He would compare his observation against the history given by the patient or the informant, in order to ascertain the likely cause of the injuries, the mechanism of how the injuries were inflicted, in order to decide and arrange appropriate medical treatment for the patient.

11. In his neurosurgery years, Dr. Pang had once again frequently come across cases involving traffic accidents, domestic falls and assaults with blunt objects. He had the experience to differentiate these causes based on his observations, and he was able to tell the common/typical injuries that would be demonstrated in each of these scenarios.

12. Further, Dr. Pang’s daily job also involved identifying and confirming the cause of death following the unfortunate demise of any of his patients. He had to do so and report his findings on the death certificate. Importantly, he had to distinguish accidental and non‑accidental causes of death, as protocol required that he referred the matter to the police and the coroner if he determined that the cause of death was non-accidental or suspicious.

13. After leaving the public sector in 2011, Dr. Pang continued his neurosurgery practice in the private sector. Being the neurosurgery consultant for several organisations/bodies in both HKSAR and China, Dr. Pang was further exposed to patients and cases in Macau, Guangzhou and Beijing. Importantly, Dr. Pang’s duty of identifying causes of death and issuing death certificates continued into the private sector.

14. Dr. Pang had various experience testifying in Hong Kong courts, especially testifying twice in the High Court for murder trials. In HCCC 265/2010, he testified as an expert in the field of neurosurgery and head trauma, and elaborated on his clinical findings. His expert status was accepted by the Court, and he was allowed to give evidence on, inter alia, the likely cause of the deceased’s injuries and the likely mechanism of infliction (i.e. in that case ‘kicking’). Although the conviction was subsequently quashed, it was on grounds unrelated to Dr. Pang's expertise. In the re-trial (HCCC 202/2013), Dr. Pang’s expert status was accepted by the Court and he was allowed to give evidence on, inter alia, the aforementioned issues. In those cases, despite expertise of Dr. Pang was not challenged by way of an voir dire, his status as an expert was accepted by the judge of the trial and then the judge of the re‑trial.”

Discussion

7.  There was no dispute between the parties that the subject matters of opinion on the disputed matters fall within the class of subjects upon which expert testimony is permissible. What was in contention is “whether the witness has acquired by study or experience sufficient knowledge of the subject to render his opinion of value in resolving the issues before the court”: see R v Bonython (1984) 38 SASR 45 (per King CJ at pp. 46-48) and Archbold Hong Kong 2025, Vol. 1 at §10-38.

8.  Mr. Arthur did not contend that only a forensic pathologist is qualified to give an opinion on the disputed matters. It is also noteworthy that Mr. Arthur did not challenge that Dr. Pang had such on-the-job training or exposure, and accumulated such clinical experience or knowledge during his practice at the different hospitals or centres as he testified. Mr. Arthur contended that notwithstanding such training, exposure and clinical experience or knowledge, Dr. Pang was not sufficiently qualified to give an opinion on the disputed areas.

9.  It should also be observed that during the voir dire, Mr. Arthur had arranged a defence expert to be present (Dr. Beh) to observe and help him assess the testimony that was being given by Dr. Pang. However, Dr. Beh did not give evidence during the voir dire.

10.  Whilst it is true that Dr. Pang had no formal qualification as a forensic pathologist, it is clear that his on-the-job training, his accumulated clinical experience and knowledge from his past practice could form the basis of his expert opinion. Examples of this may be seen in cases such as R v Marinovich (1990) 46 A Crim R 282; R v Anderson (1992) 64 A Crim R 312, 326; HKSAR v Ip Tin Wong & Ors. [2004] HKCU 466 (unreported, CACC 241/2003, 30 April 2004) and Myers v R [2016] AC 314.

11.  In light of the whole of the evidence that he gave during the voir dire, I was satisfied that Dr. Pang had acquired by study, exposure and experience sufficient knowledge of the subject matters to render his opinion of value in resolving the disputed matters before the Court. I noted that in particular, Mr. Arthur did not seriously challenge the evidence of Dr. Pang that he had the following exposure, training and clinical experience or knowledge: (1) during his years of practice at the Accident and Emergency Unit of Kwong Wah Hospital, Dr. Pang was exposed to a vast array of trauma cases caused by different types of events, such as domestic falls and assaults with blunt objects, to enable him to gain clinical experience to distinguish brain injuries and head traumas that were accidental from those that were non-accidental; (2) Kwong Wah Hospital was near Mong Kok where there were many patients sent to the hospital following gang fights and Dr. Pang was thus familiar with assault cases, including cases involving defensive injuries; (3) in his years of practice as a neurosurgeon, Dr. Pang frequently came across cases involving traffic accidents, domestic falls and assaults with blunt objects and he thus gained the experience necessary to differentiate these causes based on his observations, and he was able to tell the common or typical injuries that would be demonstrated in each of such scenarios; (4) and his daily job as a neurosurgeon also involved identifying and confirming the cause of death of his patient and reporting his findings on the death certificate, and in doing so, he had to distinguish between accidental and non‑accidental causes of death, and where appropriate, to refer the case to the police and the coroner if he determined that the cause of death was non-accidental or suspicious.

12.  Whilst Dr. Pang had no formal qualification as a forensic pathologist, I was satisfied on the strength of his evidence that he had acquired by study, exposure and experience in his years of practice sufficient knowledge of the subjects of the disputed matters to render his opinion of value in resolving the issues before the Court.

13.  I further took the view that as compared with the evidence to be given by Dr. Ying (the forensic pathologist), Dr. Pang was able to comment on some of the disputed matters (including the forces operating in cases of diffuse axonal injury on the brain) from the perspective and with the experience of a neurosurgeon, and in a case involving fatal injuries being intracerebral haemorrhage and brain damage, his expertise may enable him to better explain some of the mechanisms involved in causing such head and brain injuries.

14.  I therefore ruled that Dr. Pang was qualified to testify on such disputed matters as an expert witness and that he be permitted to so testify for the prosecution.