1. The act requirement: Without an act (or, in some cases, an omission), there is no crime.
2. The voluntariness requirement: Only voluntary actions may be punished.
3. The wrongful act of a given offence: the conduct, circumstances and consequences which, when accompanied by the requisite mens rea, comprise the material elements of a given offence.
James J. (for the majority) and Bridge J. (in dissent) agree on three points:
1. A mere omission cannot constitute an assault.
2. The criminal law does not impose a positive duty to rescue a stranger.
3. The actus reus and mens rea of a given offence must be present at the same time, but need not have commenced at the same time.
So on what point(s) do they disagree?