Defence of Honest but Mistaken Belief

In R v Johnson, the court had the opportunity to consider a defence of honest but mistaken belief: the defendant was caring for a Marijuana grow-op and, when police attended, advised that his boss had a license to grow marijuana at the residence. It was held that the defendant does not bear the onus of proving the reasonableness of the belief which, in this case, would mean reviewing the licence to ensure it existed. Rather, the onus was on the Crown to prove beyond a reasonable doubt that the defendant knew the boss did not possess a license. To find otherwise reverses the burden of proof.