The offence of dangerous driving is carefully analysed in R v Roy, 2012 SCC 26 (1 June 2012), where the appellant had been convicted of dangerous driving causing death. He had pulled out from a stop sign into the path of an oncoming vehicle. There was thickening fog and visibility was poor.
Cromwell J, for the Court, observed :
So the Court's attention in Roy was on the sensitive issue of actus reus. It is not, said the Court, the consequences (collision and death) that determine whether there was an actus reus, but the quality of the driving itself :
The Court in Roy was concerned to avoid extending the reach of the criminal law beyond what was appropriate in view of the law's purposes. It appropriately set a high level for the required harm (the actus reus) but then needlessly constrained the process of inferring the existence of the mental requirements for criminal responsibility. In Roy the trial judge had inferred mens rea from the fact that the driving was objectively dangerous, and the Supreme Court held that that was wrong . Given the thickening fog, the stop sign, the poor visibility and the oncoming traffic, the Court concluded :