The appellants were acquitted at trial of unlawfully importing heroin.
The trial judge found a reasonable doubt regarding the nature of the substance because the analyst had compared the suspect substance's graph to a standard graph of unknown preparation.
The Court of Appeal allowed the Crown's appeal and ordered a new trial, assuming the standard graph was prepared in Ottawa.
The Supreme Court of Canada allowed the appellants' appeal and restored the acquittals.
The Court held that the trial judge's factual determination regarding the analyst's procedure could not be overturned on a Crown appeal limited to questions of law.
Furthermore, the analyst's reliance on an unverified standard graph constituted 'evidence to the contrary' under s. 9 of the Narcotic Control Act, which was capable of rebutting the presumption created by the certificate of analysis.