Radio-Canada reports that Québec’s former Lieutenant-Governor, Lise Thibault, is trying to avoid having to stand trial on charges of fraud, forgery, and breach of trust, by invoking the common law rule that the Queen can do no wrong. As her lawyer puts it, criminal proceedings oppose the sovereign and the subject, and the sovereign cannot possibly sue herself. And since the charges against Mrs. Thibault relate to her time in office as the Queen’s representative in Québec, that’s what would happen if the case is allowed to go ahead.
Mrs. Thibault’s previous lawyer is apparently skeptical of the odds of her motion succeeding. So is professor Henri Brun, from Laval, whom Radio-Canada quotes saying that the principle applied in civil law―75 years ago―but criminal law is different. “As soon as a public officer commits a criminal act, he is no longer acting within his mandate; he cannot hide behind the government, behind the state” (translation mine).
That seems a little too quick. My own (admittedly quick and probably cursory) research shows that the rule that the Queen―or King―can do no wrong is, in principle, one of civil as well as one of criminal law. The Queen can do no criminal wrong, just as she can do no civil wrong. That’s the traditional common law rule, as it stood in, say, Blackstone’s time. But its import is limited in two important ways.
One is that mentioned by prof. Brun – public officers―or, to use older language, the Crown’s servants―can be sued in their personal capacity for committing criminal or tortious acts. But the question, it seems to me, is whether a Lieutenant-Governor is a public officer. This is not an area in which I am very knowledgeable, but I think that the Queen herself is not―she is not a servant of the Crown. That her servants can be criminally liable does not mean that she can. Mrs. Thibault’s argument is that she is in the same position―that she is, as it were, the Queen’s alter ego rather than her servant. I do not know whether that is correct.
The second limitation on the rule that the Queen can do no wrong has come mostly from statutes adopted by all (to the best of my knowledge) common law jurisdictions, allowing lawsuits against the Crown itself as if it were an ordinary person. Courts too have chipped away at the Crown’s immunity. But these developments, both statutory and common law, have concerned civil proceedings, not criminal. The Criminal Code, for example, does not contain a provision making it applicable to the Crown.
So if the Lieutenant-Governor is more than a mere servant of the Crown, but rather its full-blooded personification, Mrs. Thibault might have a case. If the question has never been decided though, there are surely very good reasons to opt for a restrictive interpretation of what the Crown really is. “The Queen can do no wrong” is an anachronistic rule, and its development over the last century has been a course of consistent narrowing of its ambit.
Indeed, even if there is precedent standing for the proposition that the rule protects the Lieutenant-Governor from criminal liability, the courts might want to overturn it.
Although there is something worrying in courts abolishing defences that shield the accused from liability, which is necessarily retroactive as to the accused in whose case it happens, they have sometimes done it. Two examples are the British decision of R. v. R.,  1 A.C. 599, in which the House of Lords abolished the common law rule according to which a husband could not be guilty of rape against his wife, and the American case of Rogers v. Tennessee, 532 U.S. 541 (2001), in which a sharply divided Supreme Court did away with the rule pursuant to which an accused could not be guilty of murder if the victim died more that one year and one day after the accused injured him, even though the injuries were the cause of the death. The grounds for these two rules disappeared thanks to the evolution of social morality in the first case and of medical science in the second, so that despite a certain queasiness, courts felt themselves justified in changing the common law to reflect these developments.
The common law rule that “the Queen can do no wrong” is arguably ripe for judicial intervention. Not perhaps in civil matters, where legislatures have made their own choices, which courts must respect, especially since state liability has considerable policy implications which courts might not be able to grasp. But in the narrow field of criminal offences committed by viceroys, these considerations do not apply, and there is no reason for the courts to stay their hand.