I'm certainly not an expert on Canadian law, so I'm not in a position to really comment on that. I've read some academic discussion that said that there is, in Canadian case law, a distinction between prosecutors acting in a domestic criminal case, and the role they fulfill within an extradition process. You'd have to address that question to somebody who is a Canadian expert on extradition law.
The only point I was making was that U.K. case law is very clear that within the U.K. system, even though domestic prosecutors bring the case on behalf of a foreign government, they have a duty to act, and, more specifically, they have a duty to disclose evidence that they know about, and which might destroy or undermine the evidence on which the requesting state relies. That duty overcomes their duty that they might owe as a lawyer to their client, because obviously, in that situation, they are essentially acting as a lawyer for the client, the requesting state.