The Crown appealed the acquittal of Paszczenko and Lima appealed his conviction for driving over 80.
In both cases, breath tests were taken outside the two-hour presumption window, requiring the Crown to rely on expert toxicology reports.
The central issue was how the Crown must prove the four standard assumptions underlying these reports: no bolus drinking, no post-incident drinking, a standard elimination rate, and a two-hour plateau.
The Court of Appeal held that the elimination rate and plateau are matters of scientific knowledge that courts can take judicial notice of without case-specific proof.
The assumptions of no bolus drinking and no post-incident drinking require case-specific proof, but the trier of fact may apply a common sense inference that people do not normally engage in bolus drinking, placing a practical evidentiary burden on the accused to put the issue in play.
The Crown's appeal in Paszczenko was allowed and Lima's appeal was dismissed.
