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District Court 8 August 2019

R v Delbridge

[2019] NSWDC 450

DrugsTraffic & driving
CONVICTION APPEAL PASSIVE INHALATION EVIDENCE EXPERT EVIDENCE EVIDENCE BROWNE V DUNN

Citation: R v Delbridge [2019] NSWDC 450
Court: District Court of New South Wales
Date: 8 August 2019
Judge: Priestley SC DCJ

Background

The appellant was convicted in the Local Court of driving a motor vehicle with an illicit drug present in her blood, contrary to s 111(1)(a) of the Road Transport Act 2013 (NSW). The drug detected was Delta-9-Tetrahydrocannabinol (THC), the active compound in cannabis, with a reading of 80 nanograms per millilitre in her oral fluid.

The appellant was a long-term former cannabis smoker who said she had last actively smoked cannabis approximately one to six weeks before being tested. On the day of the test, she had spent roughly two hours at home with her son and daughter-in-law, who smoked cannabis via a bong while she drank tea. She denied smoking any cannabis herself.

The central issue at both the Local Court and on appeal was whether the appellant held an honest and reasonable belief that she did not have a prohibited drug present in her blood, having regard to the possibility that her positive test resulted from passive inhalation rather than active use.

  • Whether the appellant had an honest and reasonable belief that she did not have cannabis present in her blood at the time she drove, so as to establish the Proudman v Dayman defence of honest and reasonable mistake of fact.
  • Whether the magistrate applied the correct legal test when assessing that defence.
  • How conflicting expert evidence about the possibility of passive inhalation producing a positive oral fluid test should be assessed.
  • Whether the Crown had discharged its burden of proving beyond reasonable doubt that the appellant did not hold that honest and reasonable belief.

Decision

Priestley SC DCJ conducted a full rehearing on the evidence from the Local Court proceedings, without any fresh evidence being led. His Honour noted that the appeal did not require a finding of error by the magistrate, but rather an independent assessment of the evidence.

His Honour identified a legal error in the magistrate's approach. The magistrate had framed the question as whether the appellant had satisfied him that her belief was reasonable, effectively placing the onus on the appellant. The correct approach, following the defence of honest and reasonable mistake of fact established in Proudman v Dayman, is for the Crown to prove beyond reasonable doubt that the appellant did not hold such a belief once the defendant has raised it on the evidence.

On the factual question, his Honour accepted the appellant's evidence that she genuinely believed she had not consumed cannabis and that passive exposure to others smoking would not cause her to test positive. He noted that this belief was not seriously challenged in cross-examination at the Local Court, and that no suggestion was ever put to the appellant that she had actively smoked cannabis. Significantly, the Crown's own expert, Dr Perl, was firmly of the view that passive inhalation could not account for a positive result at that concentration, which supported the reasonableness of the appellant's belief, even though a competing expert, Professor Weatherby, took a different view.

His Honour concluded that the Crown had not proved beyond reasonable doubt that the appellant's belief was either dishonest or unreasonable. The existence of credible expert opinion consistent with that belief, combined with the appellant's unchallenged evidence and her lack of prior positive tests in similar circumstances, meant a reasonable doubt existed. The conviction was set aside.

Orders Made

  • Appeal against conviction upheld.
  • Conviction and orders of the Magistrate set aside.
  • The appellant found not guilty and discharged.

Key Takeaways

  • Under the Proudman v Dayman honest and reasonable mistake of fact defence, once the defendant raises the defence on the evidence, the burden falls on the Crown to disprove it beyond reasonable doubt. The District Court held it was an error to require the defendant to positively satisfy the court that her belief was reasonable.

  • A belief that passive cannabis inhalation would not produce a positive drug driving test was found, on the facts of this case, to be capable of supporting the honest and reasonable mistake defence, particularly where credible expert opinion aligned with that belief.

  • The court's assessment of the defence was materially informed by the failure of the Crown to cross-examine the appellant on the reasonableness of her belief. The rule in Browne v Dunn is relevant to such omissions, and unchallenged evidence carried significant weight in the rehearing.

  • Conflicting expert evidence does not automatically resolve against the accused. Where one expert's evidence supports the reasonableness of the accused's belief, that can be sufficient to maintain a reasonable doubt even if a competing expert reaches a different conclusion.

  • On a conviction appeal under the Crimes (Appeal and Review) Act 2001 (NSW), the appellate court conducts a rehearing afresh on the evidence and is not confined to identifying error in the magistrate's reasoning.

Legislation and Cases Referenced

Legislation:
- Road Transport Act 2013 (NSW), s 111(1)(a)
- Crimes (Appeal and Review) Act 2001 (NSW), s 11

Cases:
- Proudman v Dayman (1941) 67 CLR 536 (honest and reasonable mistake of fact defence)
- CTM v The Queen (2008) 236 CLR 440
- Ibrahim v R [2014] NSWCCA 160
- Makita (Australia) Pty Ltd v Sprowles (2001) 52 NSWLR 705 (principles on expert evidence)
- Browne v Dunn (1893) (rule on fairness in cross-examination)