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One of the issues on appeal was the trial judge’s reliance on the evidence of some witnesses (non-experts) that Henry was impaired.
It is trite law that lay persons (non-experts) can offer an opinion on the issue of impairment by alcohol: R v Graat, 1982 SCR 819. This same view has been expressed in relation to impairment by drug – that is, that lay persons can provide an opinion that a person appeared impaired by a drug: R v Polturak, 1998 CarswellAlta 145 (CA).
Since the enactment of Bill C-2 and the provisions of the Criminal Code that provide for “drug recognition experts” to perform tests to determine if a person’s ability to operate a motor vehicle is impaired by a drug, some courts have had difficulty with this issue.