Criminal - Ignorance of the Law. R. v. Fan
In R. v. Fan (Ont CA, 2021) the Court of Appeal considered the seldom-litigated issue of 'ignorance of the law' under CCC s.19 (here contrasted with the valid defence issue of mistake of fact):
Ignorance of the Law
 The question of whether an error reflects a mistake of fact or ignorance of the law is a vexing one. However, the trial judge made no error in her characterization of the appellants’ asserted misunderstanding as a mistake of law.
 Section 19 of the Criminal Code provides that: “Ignorance of the law by a person who commits an offence is not an excuse for committing that offence”. This provision, which was enacted in 1892, codifies the common law: see Don Stuart, Canadian Criminal Law – A Treatise, 8th ed. (Toronto: Thomson Reuters, 2020), at p. 374.
 Section 19 enjoys a broad application. It applies both to “ignorance of the existence of the law and that as to its meaning, scope or application”: Molis v. The Queen, 1980 CanLII 8 (SCC),  2 S.C.R. 356, at p. 362. In this case, the appellants were aware that the production and possession of marijuana was illegal unless properly authorized. Thus, they were aware of the existence of the law; their apparent mistake pertained to its application.
 Traditionally, s. 19 applied to a person’s understanding of a statute. Today, the section applies to the existence and language of offence-creating provisions, as well as authorizations required for regulated activities, such as the possession of firearms and drugs.
 This is demonstrated in MacDonald, a decision relied upon by the trial judge, in which the accused made a mistake about the scope of his licence to possess a firearm under the Firearms Act, S.C. 1995, c. 39. The licence authorized possession only in Alberta; MacDonald was found in possession of the firearm in Halifax. MacDonald was convicted at trial.
 The Nova Scotia Court of Appeal set aside the conviction, holding that MacDonald was labouring under a mistake of fact, vitiating mens rea: 2012 NSCA 50, 317 N.S.R. (2d) 90, rev’d in part 2014 SCC 3,  1 S.C.R. 37. In restoring the conviction, the Supreme Court of Canada held, at para. 57, that given that s. 19 extended to the terms of his licence, “Mr. MacDonald’s subjective belief that he could possess the firearm in Halifax is therefore nothing other than a mistake of law.” This principle has been applied to licences under the CDSA in R. v. Vu, 2018 ONCA 436, 140 O.R. (3d) 641, at para. 67.
 To require the Crown to prove that the appellants understood the legal framework in which they operated confuses actus reus and mens rea requirements. In this context, a proper authorization or licence negates the actus reus of activity that would otherwise be illegal. Conceived as a mens rea component, it would require the Crown to prove that an accused person knew the conditions of their licence or authorization. As Lamer C.J. held in R. v. Forster, 1992 CanLII 118 (SCC),  1 S.C.R. 339, at p. 346: “[K]nowledge that one’s actions are contrary to the law is not a component of the mens rea for an offence, and consequently does not operate as a defence.” See also R. v. Docherty, 1989 CanLII 45 (SCC),  2 S.C.R. 941, at pp. 960-61.
The Complexity of the Regulatory Regime and the Appellants’ Diligence
 The appellants also rely on the fact that their conduct occurred in a complex, regulatory framework that was in a state of flux at the time. They further submit that they took steps to confirm the legality of their grown operation by consulting various sources. I am not persuaded by either argument.
 It has long been the case that s. 19 may operate in highly regulated contexts. In R. v. Jorgensen, 1995 CanLII 85 (SCC),  4 S.C.R. 55, Lamer C.J., writing for himself in a concurring judgment, addressed the feature of complexity when considering whether the concept of officially induced error of law should be introduced into Canadian law, noting at p. 29:
As several of the cases where this rule has been discussed note, the complexity of contemporary regulation makes the assumption that a responsible citizen will have a comprehensive knowledge of the law unreasonable. This complexity, however, does not justify rejecting a rule which encourages a responsible citizenry, encourages government to publicize enactments, and is an essentially foundation to the rule of law. [Emphasis added.]The Supreme Court formally recognized officially induced error in Lévis (City) v. Tétreault, 2006 SCC 12,  1 S.C.R. 420, at pp. 433-36.
 The appellants did not rely on an officially induced error of law. In their apparent attempts to confirm the legality of the grow operation, they consulted no official sources. Although they purported to rely upon the statutory declarations accompanying the licences, this was no substitute for consulting an “official” for the purposes of the officially induced error exception to s. 19: see Stucky, at para. 109. As noted above, all six licences in question disclosed a toll-free Health Canada number from which information about the licences could be obtained.
 The appellant’s reliance on their efforts to confirm legality is simply a claim that they did their best, a claim the trial judge rejected. Even if accepted, these efforts could not elude the reach of s. 19 of the Criminal Code. In La Souveraine, Compagnie d’assurance générale v. Autorité des marchés financiers, 2013 SCC 63,  3 S.C.R. 756, Wagner J. (as he then was) said, at para. 57: “A defendant can therefore gain nothing by showing that it made a reasonable effort to know the law or that it acted in good faith in ignorance of the law, since such evidence cannot exempt it from liability.” Section 19 does not reward effort; it demands correctness. Canadian jurisprudence does not recognize the concept of “a reasonable mistake of law”. To do so would undermine the rule with respect to ignorance of the law, which Lamer C.J. said in Jorgensen, at para. 5, is “an orienting principle of our criminal law which should not be lightly disturbed.”