R v Durham

[2025] NSWDC 235

District Court

New South Wales

Medium Neutral Citation:

R v DURHAM [2025] NSWDC 235

Hearing dates:

7 May 2025, 9 May 2025

Date of orders:

1 July 2025

Decision date:

01 July 2025

Jurisdiction:

Criminal

Before:

Lerve DCJ

Decision:

Verdict of guilty to the count on the Indictment

Catchwords:

Trial by judge alone – expert evidence – whether the expert for the accused is qualified to give the opinion he purports to give – driving under the influence occasioning grievous bodily harm – BAC at time of impact

Legislation Cited:

Crimes Act, 1900

Evidence Act, 1995

Road Transport Act, 2013

Cases Cited:

Atkinson v Coles Supermarkets [2020] NSWSC 1063

Cheung v The Queen (2001) 209 CLR 1

Filippou v The Queen (2015) 256 CLR 47; [2015] HCA 29

Makita (Australia) Pty Ltd v Sproules (2001) 52 NSWLR [2001] NSWCA 305

R v Bonython (1984) 38 SASR 45

Category:

Principal judgment

Parties:

Rex
Benjamin Luke DURHAM

Representation:

Counsel:
Mr P Kerr for the Crown
Mr B Hart for the Accused

Solicitors:
Mr Z Oakes, Office of the Director of Public Prosecutions
Ms B Gosling, Hosking & Gosling Legal

File Number(s):

2023/00236281

Publication restriction:

No

JUDGMENT

1. On 7 May 2025 the accused appeared at the Wagga Wagga District Court in respect of an Indictment containing one count, namely that he:

On 23 July 2023 at Memagong in the State of New South Wales, drove a vehicle, namely a white Toyota Land Cruiser with registration EWJ-14V, which was involved in an impact occasioning grievous bodily harm to Darren McManus and, at the time of the impact he was driving the vehicle under the influence of intoxicating liquor and in circumstances of aggravation, namely that the prescribed concentration of alcohol was present in his blood, contrary to s. 52A(4) of the Crimes Act, 1900.

2. The accused entered a plea of Not Guilty to that charge but pleaded guilty to the statutory alternative, i.e. a charge of Driving Under the Influence Occasioning Grievous Bodily Harm without the factor of aggravation. The Crown did not accept the plea to the alternative, and accordingly, the matter went to trial. However, there is only one matter in dispute namely whether the accused had the prescribed concentration of alcohol in his blood. The prescribed concentration of alcohol for the purposes of the section is 0.15.

3. Evidence was taken on 7 May 2025. On 9 May 2025 a timetable for submissions was set. The court is grateful to both counsel for complying with the timetable.

Factual Background

4. The matter relates to a single vehicle motor vehicle impact that occurred at about 9.25pm on 23 July 2023 at Memagong, which is near the town of Young in southern New South Wales. The accused had obviously been drinking a considerable quantity of alcohol. Darren McManus was a passenger in the Land Cruiser vehicle being driven by the accused. The vehicle impacted with a tree and as a result Mr McManus received spinal injuries, the extent of which I am not informed at this stage of the matter. The accused was arrested and a blood alcohol reading of 0.164 grams of alcohol per 210 litres of breath was obtained. The accused is diabetic and was diagnosed and treated for hyperglycaemia.

5. Both parties each called an expert pharmacologist; the Crown called Benjamin Ryan and the accused called Professor MacDonald Christie. Mr Ryan in answer to a question by me at the hearing on 7 May 2025 maintained it was not a reasonable possibility that the accused had a blood alcohol reading of under 0.15 at the time of the impact. As I understand the position of Professor Christie, he maintains that because the accused was hyperglycaemic there would have been delayed gastric emptying and that it was a reasonable possibility that the accused had a blood alcohol reading of under 0.15 at the time of the impact.

6. The Crown takes particular issue with the ability of Professor Christie to give the purported expert opinion that he does. There is no challenge to the expertise of the Professor as a pharmacologist, but there is a challenge to him being able to give an expert opinion about the endocrine system.

General Directions

7. Although the only oral evidence given was from experts it will be necessary for me to direct myself generally on a number of matters. It is for me as the tribunal of fact to assess the various witnesses and decide whether they are telling the truth. I have had the opportunity of seeing the witnesses and have had ample opportunity to observe the manner in which they gave evidence. It is entirely for the tribunal of fact to determine what evidence is accepted and what evidence is rejected.

8. My ultimate decision as to what evidence I accept and what evidence I reject may be based on all manner of things, including what the witness has had to say; the manner in which the witness said it; and the general impression which he or she made upon me when giving evidence.

9. In relation to accepting the evidence of witnesses, I am not obliged to accept the whole of the evidence of any one witness. I may, if I think fit, accept part and reject part of the same witness’ evidence. The fact that I do not accept a portion of the evidence of a witness does not mean that I must necessarily reject the whole of the witness’ evidence. It does not mean that I should not accept the remainder of that evidence if I think it is worthy of acceptance. This being a Judge Alone trial, it will be necessary for me to give reasons as to why I accept or reject the whole or part of the evidence of any one particular witness.

10. As the tribunal of fact, I am entitled to use life experiences, training and experience as a lawyer and as a judicial officer. I can make a value judgment. However, I cannot use that experience to make findings of fact or to draw inferences unless that personal experience satisfies the test relating to common knowledge in s 144 of the Evidence Act, 1995.

11. I have heard addresses from counsel for the Crown and counsel for the accused. I will consider those submissions that have been made in their addresses and give to the submissions such weight as I think fit. In no sense are those submissions evidence in the case.

Inferences

12. This is a matter where I am asked to draw inferences. I remind myself and direct myself in terms of what juries are normally directed on the drawing of inferences. Inferences are conclusions of fact rationally drawn from a combination of proven facts. If A, B and C are established as facts, then one might rationally conclude that D is also a fact, even though there might be no direct evidence that D is indeed a fact. Inferences may be valid or invalid, justified or unjustified, correct or incorrect.

13. I remind myself of the illustration routinely given to juries from the Trials Bench Book of the telephone call to a friend. In a criminal trial, as the tribunal of fact, I must be satisfied of the guilt of the accused beyond reasonable doubt. Amongst other things, that means that I should be extremely careful about drawing any inference. I must examine any possible inference to ensure that it is a justifiable inference.

14. In the context of a criminal trial, where proof is required beyond reasonable doubt, as the tribunal of fact I must not draw any inference from the direct evidence unless it is the only rational inference in the circumstances.

CCTV

15. Both Mr Ryan and Professor Christie gave their evidence from various remote (from the court and indeed Wagga Wagga) locations by audio visual link. There is nothing unusual or exceptional about that in this day and age and so far as trials in rural and regional areas are concerned is quickly becoming the norm rather than the exception. I must give the evidence no greater or lesser weight.

Onus and burden of proof

16. I go to what is undoubtedly the most important direction of any criminal trial; that is the direction relating to the onus and burden of proof. Before I could return a verdict of guilty in respect of the count on the Indictment that is before me the Crown would need to prove the guilt of the accused and prove that guilt to the criminal standard of beyond reasonable doubt. The words “beyond reasonable doubt” are ordinary English words and they are given their ordinary English meaning. The collective legal wisdom developed over the centuries is that further elaboration by trial judges on the meaning of the expression “beyond reasonable doubt” is neither necessary nor desirable. However, as part of the direction on the onus and burden of proof I direct myself that suspicion, even the gravest of suspicion, cannot amount to proof beyond reasonable doubt.

17. If, at the end of my deliberations, having taken into consideration the evidence for the Crown and evidence led in the accused’s case in respect of any matter which the Crown must establish to make out its case, and after also taking into consideration the submissions made to me by the Crown and counsel for the accused in their address, I am not satisfied that the Crown has established any one of these essential matters beyond reasonable doubt then it is my duty, as I have said, to bring in a verdict of "not guilty", because the Crown will have failed to do what the law requires it to do.

18. I remind myself that it is vitally important that I clearly understand that the accused must be found "not guilty" if his guilt has not been proved to my satisfaction beyond reasonable doubt. It follows from this, of course, that if I am left unable to decide whether the Crown has proved its case in relation to any such essential ingredient, if I have a reasonable doubt in respect of that matter, the accused is entitled to the benefit of that doubt and I must find him “not guilty”.

Essential elements

19. In order for me as the tribunal of fact to return a verdict of guilty to the count on the Indictment, the Crown would need to prove the following essential elements or ingredients:

1. The accused was the driver of a motor vehicle;

2. which was involved in an impact; and

3. as a result of that impact Darren McManus sustained grievous bodily harm; and

4. the accused was driving under the influence of alcohol; and

5. there was the prescribed concentration of alcohol present in the accused’s blood, i.e. no less than 0.150 milligrams of alcohol in 100 millilitres of blood.

20. The essential elements of the statutory alternative to which the accused has entered a plea of guilty, which was not accepted by the Crown in full satisfaction of the Indictment, are:

1. The accused was the driver of a motor vehicle;

2. which was involved in an impact; and

3. as a result of that impact Darren McManus sustained grievous bodily harm; and

4. the accused was driving under the influence of alcohol.

21. Given the manner in which this case has been conducted and in particular the plea of guilty to the statutory alternative, it occurs to me that it is unnecessary to give any further explanation of the essential elements or ingredients of the charges under consideration.

Accused remains silent

22. The accused did not give evidence. An accused is entitled to give or call evidence in respect of any aspect of the Crown’s case, however, an accused is equally entitled to put the Crown to proof and require the Crown to prove his or her guilt beyond reasonable doubt. As the tribunal of fact, I must draw no inference adverse to the accused because he did not give evidence. The onus and burden of proof is on the Crown from beginning to end to the criminal standard of beyond reasonable doubt. There may be good reasons why an accused would not give evidence and as the tribunal of fact I must not speculate on what they may be. The absence of evidence from the accused cannot be used as a make-weight in determining whether the Crown has proved its case beyond reasonable doubt nor can it be used to plug or fill gaps I perceive in the evidence. At the risk of repetition, no inference adverse to the accused must be drawn because he did not give evidence and the onus and burden of proof is on the Crown from beginning to end.

23. In this matter however, the accused did not remain silent in the course of the investigation. The agreed facts state that the accused entered into a record of interview. That record of interview is not part of the material that is before me. In the circumstances of what falls for determination in this matter that is hardly surprising.

Expert Witnesses

24. Two expert witnesses were called to give evidence. Mr Benjamin Ryan was called by the Crown and Professor MacDonald Christie was called on behalf of the accused.

25. Both Mr Ryan and Professor Christie are pharmacologists. Both have provided an Expert’s Certificate pursuant to s 177 of the Evidence Act, 1995. Both gave oral evidence via audio visual link on 7 May 2025.

26. An expert witness is a person who has specialised knowledge based on that person’s training, study or experience. Unlike other witnesses, a witness with such specialised knowledge may express an opinion on matters within his or her particular area of expertise. Other witnesses may speak only as to facts - that is, what they saw or heard - and are not permitted to express their opinions.

27. Appropriately, no issue is taken with the expertise of any of either of the experts so far as pharmacology is concerned. The Crown takes particular objection to Professor Christie purporting to give an expert opinion as to the endocrine system of the human body. The Crown Prosecutor objected a number of times to the evidence of Professor Christie at the hearing on 7 May 2025. I took the view then, and remain of the view, that it was inappropriate to have dealt with that objection quickly on the day.

28. However, both experts are particularly well qualified and extremely well experienced in the field of pharmacology.

29. The weight of any expert opinion is dependent on the reliability and accuracy of the material which the expert used to reach his or her opinion. The weight of the expert opinion is also dependent upon the degree to which the expert analysed the material upon which the opinion was based and the skill and experience brought to bear in formulating the opinion given.

30. Experts can differ in the level and degree of their experience, training and study, yet each can still be an expert qualified to give an opinion where that opinion is based on that witness’s specialised knowledge.

31. I note that in this matter there was broad agreement between the experts but they disagree on whether it is a reasonable possibility that the accused had a blood alcohol reading of less than 0.15 at the time of the impact. I will deal with these issues in the course of dealing with the facts and the evidence.

32. In the present case, in relation to particular issues there is conflict in the evidence between the expert witnesses. It is not a matter of simply choosing between their evidence as a matter of simple preference. In resolving the conflict between the evidence of the expert witnesses I must always keep in mind that it is for the Crown to prove its case beyond reasonable doubt. It is for me to decide whose evidence and whose opinion I accept in whole or in part, or whose evidence I reject altogether. I should keep in mind that in reaching a verdict I must consider all the evidence. In resolving any conflict in the expert evidence, I am entitled to consider that particular evidence in the context of all of the evidence before me.

33. Expert witnesses are required to comply with Schedule 7 of the Uniform Civil Procedure Rules. Lonergan J in Atkinson v Coles Supermarkets [2020] NSWSC 1063 said at [23] “Schedule 7 of the UCPR provides the expert Code of Conduct. This is not a meaningless incantation.”

Agreed Facts

34. Exhibit C in the trial is a comprehensive set of agreed facts. Pursuant to s 191 of the Evidence Act, 1995 the parties agree that:

1. The accused is Benjamin Durham born on 17 July 1991.

2. At about 9.25pm on 23 July 2023 the accused was the driver of a white Toyota Land Cruser, NSW registration EWJ-14V when that vehicle was involved in an impact with a tree on Milly Milly Lane, Burrangong (Young).

3. Darren McManus, who was seated in the passenger seat of the vehicle driven by the accused, suffered grievous bodily harm as a result of the impact.

4. The accused was 32 years old at the time of the incident. He held a valid NSW driver’s licence issued to him on 11 October 2018.

5. Police arrived at the scene of the incident at 9.41 pm. The accused failed a roadside breath test conducted at about 9.45 pm.

6. The accused told police:

1. He commenced drinking alcohol at about 2.00pm on 23 July 2023;

2. He had his last drink at about 7.00pm, at which time he ate a “full baked dinner”; and

3. At the time he was breathalysed at the collision site that he had had “a few drinks” and when asked how many responded, “Can’t tell ya”.

7. The accused was arrested and transported by police to the Young Police Station.

8. While at the Young Police Station, the accused said he had consumed five to ten drinks of “various sizes of port and beer”.

9. NSW police requested an ambulance to treat the accused in custody at 10.07pm.

10. At 10.24pm the accused underwent a breath analysis conducted in accordance with Schedule 3 of the Road Transport Act 2013.

11. The concentration of alcohol in the accused’s breath at 10.24 pm was 0.164 grams of alcohol in 210 litres of breath.

12. The accused was treated at the police station by NSW Ambulance Officers at 11.51pm.

13. The accused was diagnosed and treated for hyperglycaemia by NSW Ambulance officers and transported to hospital.

14. At 12.38 am on 24 July 2023 a sample of the accused’s blood was taken in accordance with Schedule 3 of the Road Transport Act, 2013.

15. The Blood Alcohol Concentration (BAC) in the accused’s blood at 12.38am was 0.146 grams of alcohol in 100 millilitres of blood.

16. The accused’s NSW Driver’s Licence was suspended.

35. Those agreed facts enable me as the tribunal of fact to find beyond reasonable doubt that on 23 July 2023 the accused was driving a motor vehicle while under the influence of intoxicating liquor when the vehicle was involved in an impact as a result of which Darren McManus sustained grievous bodily harm.

First Report of Benjamin Ryan

36. Mr Ryan is a forensic pharmacologist and a pharmacist employed by the New South Wales Police Force. His qualifications are Bachelor of Medical Science (University of Technology, Sydney) and Master of Pharmacy (University of Sydney). He has gained full registration as a pharmacist to practice in Australia and he has several years of experience in areas of practice. He has received specialist training in clinical forensic pharmacology and its application to driver impairment. I note that there is no challenge to Mr Ryan’s expertise but his experience is set out in detail on page 1 of his Certificate.

37. For the purpose of preparation of the report, Mr Ryan makes a number of assumptions that are set out at pages 2 and 3 of his Certificate. At paragraph 1 under the heading “Assumptions” it is set out that at about 9:27pm on 23 July 2023 the accused Benjamin Durham left his property driving a utility vehicle with a front passenger and after having travelled approximately 1 km he allegedly lost control of his vehicle around a left hand bend before colliding with a tree. The accused’s vehicle rolled onto the passenger side and the accused was able to free himself before calling emergency services. The front passenger was trapped in the vehicle and later found to have suffered significant spinal injury.

38. Acting Sergeant Tajsic arrived on the scene at about 9:41pm and observed the vehicle on its side in a ditch. The accused had a slight smell of intoxicating liquor on his breath, he had redness to his face, his speech and responses appeared to be delayed, his movements appeared sluggish and his eyes appeared to be bloodshot and glazed. The officer formed the opinion that the accused was well affected by alcohol. The remainder of what appears under the heading assumptions is essentially what is contained in the agreed facts set out above within these reasons.

36. Under the heading “opinion” Mr Ryan sets out:

“When alcohol is consumed, the blood alcohol concentration (BAC) begins to rise (the absorption phase) within minutes of commencing to drink and as soon as alcohol enters the bloodstream it is metabolised by the liver. However, elimination occurs at a steady rate and if the amount of alcohol being absorbed exceeds the elimination rate then the BAC continues to rise. After drinking ceases it will continue to rise normally for a period of 20 to 40 minutes if no substantial meal is consumed during drinking. Food can delay the time to peak, but at the drinking period is over several hours and drinking is at a relatively steady rate, then the peak will still be expected to occur at the end of drinking or around 30 minutes after the last drink.

…

From the time drinking commences, the body is also eliminating alcohol and the BAC declines (due to elimination) at a generally steady rate, but which varies between individuals. Human elimination rates of alcohol range from 0.010 g per 100 mL per hour to 0.025 g per 100 mL per hour… although the generally accepted most likely rate of elimination is considered to be around 0.015 g/100mL per hour and the general population.”

40. Mr Ryan opines that given the drinking history provided by the accused to police in which he was drinking alcohol over a five hour period, finishing at about 7.00pm and included a significant meal he would expect that by the time of the impact the accused would have been past his peak BAC.

41. Further Mr Ryan goes on to opine that based on the breath analysis result and the rates of elimination at the time of the collision the accused’s BAC would have been not less than 0.174 g/100 ml with an upper limit of 0.188 g/100 ml and most likely BAC of 0.178 g/100ml. Based upon the blood result and the rates of elimination, at the time of the collision the accused BAC would have been not less than 0.178 g/100 ml with an upper limit of 0.226 g/100 ml and are most likely BAC of 0.194 g/100 ml.

42. Mr Ryan further sets out at paragraph 5 on page 4 of his Certificate that at a blood alcohol concentration of 0.05 to 0.08 g per 100 ml, a “social” drinker of any age would be expected to have some impairment of driving ability, in particular in relation to emergency reaction skills and the more complex skills required in the driving task. Above 0.08 g per 100 ml even some general driving skills would be impaired and above 0.10 grams per 100 ml there would be significant impairment of driving ability in all people. At a BAC of 0.15 g per 100 ml and above there would be very substantial impairment of driving ability in all people.

43. Mr Ryan then sets out some of what is contained in the scientific literature relating to alcohol induced impairment of skills performance and psycho motor tasks. I do not understand any of that to been dispute in this case.

44. Not surprisingly, given what is contained above, at paragraph 8 Mr Ryan sets out that at a BAC of 0.174 g/100 ml and above all people would be under the influence of alcohol to the extent that there would be very substantial impairment of driving ability. Driving ability includes the concurrent use of cognitive, motor and visual functions such as reaction skills, tracking ability, motor coordination, judgement, perception, decision-making, visual scanning and peripheral vision, which all would be very substantially impaired at a BAC of 0.174 g/100 ml and above.

45. Mr Ryan concludes that a BAC of 0.174 g/100 ml or above at the time of the collision, the accused would have been under the influence of alcohol to the extent that his driving ability would have been very substantially impaired.

Report of Professor Christie

46. Initially I note that at paragraph 4 on page 3 of his report the Professor says:

“I, Professor MacDonald Christie acknowledge for the purpose of, rule 31.23 of the Uniform Civil Procedure Rules 2005 that I have read the expert witness code of conduct in Schedule 7 to the said rules and agree to be bound by it. To the best of my ability this report has been prepared in accordance with the Code”.

47. At paragraph 6.3 on page 8 of his report Professor Christie says:

“If I had not received the information that your client had ingested full baked dinner at 7;00pm with a drink (and had presumably been drinking consistently before that) and, more importantly, that he suffers from Type I diabetes and was hyperglycaemic after dinner, I would have calculated the same ranges of likely BAC for your client that performed above (and by Mr Ryan) on the assumption of complete absorption of alcohol from his digestive track into the bloodstream by the time of the accident at around 9:30pm.”

48. The Crown objects to Professor Christie giving the opinion that is set out at page 7 of his report and the following namely:

“All of these studies support the conclusion that that a substantial proportion of your client’s last drinks probably remained unabsorbed from his digestive system into his bloodstream at 9.30 pm. His type 1 diabetes and hyperglycaemia during the evening strengthen this concern, suggesting that back calculation of BAC from these measurements in inappropriate.

At best on the basis of this uncertainty it would be most reasonable to conclude that your client’s BAC was below 0.15% at 9.30pm, similar to the value of the roadside test and could have been higher or lower than that value and could reasonably have subsequently risen due to continued absorption of alcohol into his bloodstream to produce the readings at 10.24pm and 12.38pm (sic but read am)”.

49. The objection taken by the Crown is that Professor Christie is not qualified to give the opinion he purports to give as he is a pharmacologist and not an endocrinologist.

50. Section 76 of the Evidence Act, 1995 provides:

The opinion rule 

(1)       Evidence of an opinion is not admissible to prove the existence of a fact about the existence of which the opinion was expressed.

(2)       Subsection (1) does not apply to evidence of an opinion contained in a certificate or other document given or made under regulations made under an Act other than this Act to the extent to which the regulations provide that the certificate or other document has evidentiary effect.

Note— Specific exceptions to the opinion rule are as follows—

•  summaries of voluminous or complex documents (section 50 (3))

•  evidence relevant otherwise than as opinion evidence (section 77)

•  lay opinion (section 78)

•  Aboriginal and Torres Strait Islander traditional laws and customs (section 78A)

•  expert opinion (section 79)

•  admissions (section 81)

•  exceptions to the rule excluding evidence of judgments and convictions (section 92 (3))

•  character of and expert opinion about accused persons (sections 110 and 111).

Other provisions of this Act, or of other laws, may operate as further exceptions.

Examples:

¹     P sues D, her doctor, for the negligent performance of a surgical operation. Unless an exception to the opinion rule applies, P’s neighbour, W, who had the same operation, cannot give evidence of his opinion that D had not performed the operation as well as his own.

²     P considers that electrical work that D, an electrician, has done for her is unsatisfactory. Unless an exception to the opinion rule applies, P cannot give evidence of her opinion that D does not have the necessary skills to do electrical work.

51. Section 79 of the Evidence Act provides:

79   Exception: opinions based on specialised knowledge 

(1)       If a person has specialised knowledge based on the person’s training, study or experience, the opinion rule does not apply to evidence of an opinion of that person that is wholly or substantially based on that knowledge.

(2)    To avoid doubt, and without limiting subsection (1)—

(a)  a reference in that subsection to specialised knowledge includes a reference to specialised knowledge of child development and child behaviour (including specialised knowledge of the impact of sexual abuse on children and their development and behaviour during and following the abuse), and

(b) a reference in that subsection to an opinion of a person includes, if the person has specialised knowledge of the kind referred to in paragraph (a), a reference to an opinion relating to either or both of the following—

(i)  the development and behaviour of children generally,

(ii)  the development and behaviour of children who have been victims of sexual offences, or offences similar to sexual offences.

52. Hayden JA (as his Honour then) (Priestly & Powell JJA agreeing, both with brief additional comments) said in Makita (Australia) Pty Ltd v Sproules (2001) 52 NSWLR [2001] NSWCA 305 at [85]-[86]:

“In short, if evidence tendered as expert opinion evidence is to be admissible, it must be agreed or demonstrated that there is a field of ‘specialised knowledge’; there must be an identified aspect of that field in which the witness demonstrates that by reason of specified training, study or experience, the witness has become an expert; the opinion proffered must be ‘wholly or substantially based on the witness’s expert knowledge’; so far as the opinion is based on facts ‘observed’ by the expert, they must be identified and admissibly proved by the expert, and so far as the opinion is based on ‘assumed’ or ‘accepted’ facts, they must be identified and proved in some other way; it must be established that the facts on which the opinion is based form a proper foundation for it; and the opinion of an expert requires demonstration or examination of the scientific or other intellectual basis of the conclusions reached: that is, the expert’s evidence must explain how the field of ‘specialised knowledge’ in which the witness is expert by reason of ‘training, study or experience’, and on which the opinion is ‘wholly or substantially based’, applies to the facts assumed or observed so as to produce the opinion propounded. If all these matters are not made explicit, it is not possible to be sure whether the opinion is based wholly or substantially on the expert’s specialised knowledge. If the court cannot be sure of that, the evidence is strictly speaking not admissible, and, so far as it is admissible, of diminished weight. And an attempt to make the basis of the opinion explicit may reveal that it is not based on specialised expert knowledge, but, to use Gleeson CJ’s characterisation of the evidence in HG v R (1999) 197 CLR 414, on ‘a combination of speculation, inference, personal and second-hand views as to the credibility of the complainant, and a process of reasoning which went well beyond the field of expertise" (at [41]).

[86]    That statement of the law corresponds with the views of Black CJ, Cooper J and Emmett J in Ocean Marine Mutual Insurance Association (Europe) OV v Jetopay Pty Ltd [2000] FCA 1463 at [21]-[23]:

‘[21] The primary judge considered that it was permissible to examine the reports and draw inferences from the form and contents of them. His Honour considered that it was permissible to take into account:

· the factual context in which a report was produced;

· the description and designation of the person making the report;

· the contents and language of the report and the nature of the assertions made in it;

· the form of the report;

· the expressed qualifications of the person making it as set out in the report.

[22] However, it is not permissible to conclude from those matters alone that an author of a report has any specialised knowledge, except to the extent that the report states (or it otherwise appears from admissible evidence) what that knowledge is. Nor is it permissible, by reason of those matters alone, to conclude that any specialised knowledge that the author of a report has is based on any training, study or experience of the author. Thus, it is not permissible to conclude, simply because a person expresses an opinion on a particular subject, referring to particular technology, that that person has any specialised knowledge in relation to that subject. There must be specific evidence as to specialised knowledge of the person in relation to that subject and as to the training, study or experience upon which that specialised knowledge is based.

[23] The further requirement that an opinion be based on specialised knowledge would normally be satisfied by the person who expresses the opinion demonstrating the reasoning process by which the opinion was reached. Thus, a report in which an opinion is recorded should expose the reasoning of its author in a way that would demonstrate that the opinion is based on particular specialised knowledge. Similarly, opinion evidence given orally should be shown, by exposure of the reasoning process, to be based on relevant specialised knowledge."

The last quoted paragraph was applied by Einstein J in Idoport Pty Ltd v National Australia Bank Ltd [2001] NSWSC 123 at [19]. Evidence not complying with the principles described in it might be inadmissible as irrelevant (s 56(2)), as not complying with s 79, or on discretionary grounds (s 135). However, no objection was taken to Professor Morton’s evidence, so the only issue for this Court is its weight.”

53. As the Crown notes in their written submissions, the expression “specialised knowledge” is not defined in the Evidence Act. The Crown refers me to the South Australian decision of R v Bonython (1984) 38 SASR 45. Although now of some age and from a different jurisdiction and one in which the Uniform Evidence Act does not apply, that decision is of some utility. King CJ (Matheson & Bolleson JJ agreeing, both with additional comments) said at 46-47:

“Before admitting the opinion of a witness into evidence as expert testimony, the judge must consider and decide two questions. The first is whether the subject matter of the opinion falls within the class of subjects upon which the expert testimony is permissible. The first question may be divided into two parts: (a) whether the subject matter of the opinion is such that a person without instruction or experience in the area of knowledge or human experience would be able to form a sound judgment on the matter without the assistance of witnesses possessing special knowledge or experience in the area, and (b) whether the subject matter of the opinion forms part of a body of knowledge or experience which is sufficiently organised or recognised to be accepted as a reliable body of knowledge or experience, a special acquaintance with which by the witness would render his opinion of assistance to the court. The second question 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”.

54. Going to the evidence of Professor Christie, the following appears at p 26:21ff of the transcript of the hearing on 7 May 2025:

“Q.  In respect of that ‑ and I'm going to go back to your curriculum vitae and your experience ‑ some of the opinions which you profess to make, relate to type I diabetes and the effect that that has on the digestive system and alcohol being absorbed into the blood.  What can you tell the Court about your experience in that field?

A.  I had, before this matter came to me, I had little experience of alcohol absorption in either type 1 or type 2 diabetes, but I needed to consider that because I knew that diabetes affects the gastrointestinal system or the intestinal system.  I needed to seek out information in the literature, as a physiologist and pharmacologist that I am, that might suggest that emptying of the stomach which is one of the ‑ which is really the basis of the rate of emptying of the stomach ‑ the basis of when blood alcohol concentration reaches a peak and enters the elimination phase.

And I very rapidly found the article that we've been referring to of Goyal which really is a very prominent review article in the most prestigious medical journal in the world ‑ the New England Journal of Medicine, maybe rivalled by the Lancet in London, but certainly up, number 1, number 2 ‑ which is a review and summary for the medical specialist of gastric emptying abnormalities in diabetes.  I found that in the literature very quickly and then delved into the deeper literature of gastric emptying in diabetes.

I also researched and sought out information as to whether diabetes affects the rate of elimination of alcohol from the body.  Once fully absorbed there's no evidence that it affects the rate of elimination.”

55. Then at p 27:44, Mr Hart for the accused asked Professor Christie:

“In relation to hyperglycaemia, that wouldn’t come within your ambit as a pharmacologist, but do you in your professional career have any knowledge of hyperglycaemia and how that would affect the body’s uptake of alcohol?”

56. The Crown then objected on the basis that it was outside the Professor’s area of expertise, and in particular the Crown put (p 28:12):

“…You can't become an expert in a month.  He was briefed on 9 May.  The report's dated 2 June.  You cannot become an expert with specialised knowledge in a particular area by reading other people's reports of which you have no training or experience in as an endocrinologist in a period of a month and become an expert who is entitled to give expert evidence in a court.”

57. I observe that the Professor in his evidence, particularly under cross-examination was utterly dogmatic and emphatic. Further, he appeared to me to be utterly resentful of any challenge. At p 29:12 the following appears:

“Of course I have knowledge of type 1 diabetes as a general pharmacologist but also as a general physiologist and as, frankly a leading academic in the field of medical science with an ability to deeply analyse literature from vastly different areas, which I’ve been doing for over 40 years”.

58. One of the reports to which the Professor had reference is at tab 4 of exhibit D, namely “Gastric Emptying Abnormalities in Diabetes Mellitus” by Raj K. Goyal MD. The Professor gave evidence at p 29:20 that he was not aware of that report until he began his research for the matter presently under consideration.

59. The Crown Prosecutor cross-examined the Professor as to his expertise in endocrinology. The following appears at p 34:29 – p 35:11:

“Q. In your report – you’ve been through this, I’ll be quick – you say that you are a Professor of Pharmacology and you specialist in actions of drugs and alcohol in the brain and brain function; is that correct?

A. That’s my specialty.

Q.  That's your area of expertise, isn't it?

A.  Well, that's the area that I'm a world leader in, yes.

Q.  In your CV you refer to yourself as a neuropharmacologist.  Is that a specialised field within the field of pharmacology?

A.  It's a field of training within the field of pharmacology, and a subdiscipline within pharmacology, and it was the area that I always led teaching it.

Q.  You haven't received any formal training as an endocrinologist, have you?

A.  No, I haven't.

Q.  You have no experience in the field of endocrinology?

A.  Only where it intercepts with pharmacology.

Q.  You have no qualifications in the area of the endocrine system?

A.  I have no specific qualifications in the field of the endocrine system which would be a medical specialist in endocrinology.

Q.  You don't have any level, is it true, of specialised knowledge in the medical field of endocrinology or diabetes?

A.  No, I have a substantial understanding of endocrinology and some understanding of diabetes in the medical field because that is my business as a physiologist, pharmacologist.  I have to consider abnormal physiology in relation to drugs, so I need to understand a vast range of abnormal physiologies.

Q.  You have specialised knowledge based on your training, study or experience in the medical field of diabetes.

A.  Not in the medical field of diabetes, it the scientific field.”

60. Further beginning at p 35:43:

“Q.  Do you say to his Honour that you can become an expert with specialised knowledge on a particular area of medicine by simply doing some research and reading some papers?

A.  Sir, that is my profession as a senior scientific academic in a medical field, and it is my duty as such an academic both as a researcher, as a person who publishes in many fields of the influence of drugs on the body and pathology, and as a journal editor of leading scientific medical journals, it is my duty to do that and it is something that I've been doing for well over 30 years.   

Q.  So you generally believe that it is your duty, and I accept you may believe that, but it doesn't make you an expert in the field, does it?

A.  It doesn't make me an expert in the field of everything to do with diabetes, but with respect it has always been my scientific duty, or discipline if you will, to actually undertake ‑ to undertake to understand with my breadth of scientific medical knowledge any intersections of fields.  Indeed pharmacology is replete with that problem because drugs affect so many body systems in so many pathologies.  So to be an expert, Professor of Pharmacology in a general sense requires deep understanding of the ability to extract information from any medical field, and I do claim that I have that ability.

Q.  Your tone in the articles that you refer to in your report specifically for the purpose of responding to the request made of you by Ms Gosling who is a solicitor who appears for Mr Durham; is that right?

A.  Yes.

Q.  And everything you know about the interaction between type 1 diabetes and how it might affect the metabolism of alcohol came from those articles.

A.  It also came ‑ it came not only from those articles, it also came from the absence of articles, and that I searched many many terms for elimination of alcohol across 36 million studies and found none.  So I concluded that there was no evidence for that.  When I searched across the influence of diabetes on gastric emptying, there was substantial literature which is referred to by Goyal in a summary study, and I felt that summary study was sufficient once I had fully digested the study.

Q.  You would have learned from your reading that not all people with type 1 diabetes experience gastric emptying issues.

A.  No, that's variable, but that's variable in the absence of hyperglycaemia, and that is the point of the paper.  There are many people with diabetes who suffer from chronic delayed gastric emptying, and suffer many problems because of that.”

61. The last part of the answer to the Crown Prosecutor’s question that begins at p 36:16 is particularly significant so far as the Crown’s objection is concerned. At the risk of repetition, namely, “…When I searched across the influence of diabetes on gastric emptying, there was substantial literature which is referred to by Goyal in a summary study, and I felt that summary study was sufficient once I had fully digested the study”.

62. The Crown’s position is quite clear and can be easily stated as that I should not admit the evidence from Professor Christie as he does not have the necessary expertise to give the opinion that he purports to give.

63. Mr Hart on behalf of the accused maintains that he is qualified. The Professor’s curriculum vitae runs to some 24 pages. Some of the highlights are emphasised at paragraph 3 and continuing of Mr Hart’s written submissions and include being awarded a PhD in the Department of Pharmacology at the University of Sydney, a Distinguished Professional Achievement Award in 2018 and in 2021 the Clarivate Highly Researcher Award which is awarded to the top 0.1% of researchers. Professor Christie is published in 237 peer-reviewed journal articles, has co-authored four text books and authored three reports for government bodies.

64. There is no doubt that Professor Christie is truly eminent in his field. He is undoubtedly highly accomplished and although it came across in his evidence as being somewhat boastful, he is a world leader in his field. I do not resile from my observations that he was dogmatic and resented being challenged. I accept that an eminent academic such as Professor Christie would be resentful of being challenged. Those are merely my subjective observations and play no part in the ultimate decision of this matter.

65. Ultimately, however, the Crown’s objection is made good. While Professor Christie is undoubtedly a world class expert in his field, it cannot be the case that he can become an expert in another in a period of a few weeks by reading some articles. I therefore reject Professor Christie’s evidence. What Professor Christie did is in essence no different to any medical specialist e.g. a cardiologist spending several weeks reading medical journal articles. The Crown’s submission that someone cannot become an expert in a little over three weeks is made good.

66. If I am incorrect in dealing with the evidence by rejecting the evidence, noting that I allowed some considerable latitude at the hearing on 7 May 2025, if the opinion of Professor Christie should have been admitted then for the reasons given I would give it so little weight as it would have no effect.

67. There are further reasons why the opinion of Professor Christie in the circumstances of this case should carry little or no weight. Mr Hart noted in his written submissions that at the hearing I noted that Professor Christie did not provide a back calculation when giving the opinion that it was reasonably possible that the accused at the time of the impact had a BAC of less than 0.150. Professor Christie merely opines that it was reasonably possible that the accused had a BAC of under .150 at the time of the impact.

68. On this aspect the Crown puts at paragraph 10 of his submissions that “He (Professor Christie) simply opined that the accused’s BAC would, at the time of the collision, have been under 0.150, conveniently below the level that elevates the offence to the aggravating (sic) category”. To my mind there is very real substance in the Crown’s submission in this regard.

69. That part of the Professor’s evidence contained some of the briefest and most concise answers in his evidence:

“HIS HONOUR

Q.  I'll ask you the same question that asked Mr Ryan.  Is it a reasonable possibility in your opinion that the accused was under 0.15 at the time of the impact?

A.  Yes.

Q.  And that reasonable possibility, Professor, is based on your understanding of the effect of type 1 diabetes on gastric elimination?

A.  It's based on that, but together with the fact that there is some uncertainty with that timelapse even in normal individuals.  I just believe that diabetes exacerbates that.

Q.  You say it's a reasonable possibility that Mr Durham's blood alcohol level was below 0.150 at the time of the collision, but you can't say what it was?

A.  No.

Q.  Just below, below that critical point in these proceedings.

A.  No, I've said no to that.”

70. The agreed facts establish that the accused was subject to an evidential breath test at 10.24pm and the reading was 0.164 grams of alcohol per 210 litres of breath. As I understand the medical journal articles within exhibit D, it is generally accepted that the breathalyser will generally produce a slightly lower reading than that obtained from a blood test. In the matter presently under consideration the agreed facts also set out that blood was taken at 12.38am and that produced a reading of 0.146, a reading which I note is only marginally below 0.150 and which was obtained long after the last drink and three hours after the impact.

71. The time of the blood sample being taken was approximately three hours after the impact and five and one half hours after the accused imbibed his last drink. The fact that the blood test produced a lower reading than that obtained some two hours earlier surely indicates that by the time the blood sample was taken the accused was in the elimination phase. It is clear from paragraph 2c of Mr Ryan’s initial report that calculations were also done on the basis of the result of the blood test.

72. Mr Hart submits that the Crown did not object to a question by me at p 19:10, namely:

“Q:   I’m sorry Mr Ryan, but is that a long way of saying that the opinion that the type 1 diabetes would have further delayed time to its peak to the extent that BAC may have been below 0.150 is purely speculative?

A:   Yes, I’d agree that it’s speculative.”

73. That question by me followed the last question in evidence in chief from the Crown. I asked that question to ensure that I properly understood the answer. Given it was simply me attempting to ensure that I understood an answer to the Crown’s question I am not sure on what basis the Crown could have objected. I do not see the lack of objection by the Crown to that question by me assists the accused. The fact remains on the material before me it is entirely speculative as to whether the accused’s diabetes delayed the absorption of the undoubted very substantial quantity of alcohol that the accused had consumed.

Conclusion and Verdict

74. With the opinion of Professor Christie to one side then the verdict is inevitable.

75. Benjamin Durham, in respect of the charge that you:

On 23 July 2023 at Memagong in the State of New South Wales, drove a vehicle, namely a white Toyota Land Cruiser with registration EWJ-14V, which was involved in an impact occasioning grievous bodily harm to Darren McManus and, at the time of the impact he was driving the vehicle under the influence of intoxicating liquor and in circumstances of aggravation, namely that the prescribed concentration of alcohol was present in his blood, contrary to s 52A(4) of the Crimes Act, 1900.

I find you guilty.

Addendum

76. Given the verdict I have just announced, I apprehend it is likely (or perhaps inevitable) that there will be factual dispute as to what I should find so far as the actual blood alcohol reading was at the time of the impact for the purpose of sentence.

77. Noting the decisions of Cheung v The Queen (2001) 209 CLR 1 at [14] per Gleeson CJ, Gummow & Hayne JJ and Filippou v The Queen (2015) 256 CLR 47; [2015] HCA 29 at [64] my preliminary view, subject to submissions is that I would sentence on the basis of the reading set out at paragraph 11 of the agreed facts.

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Decision last updated: 07 August 2025