Section 408 in the Criminal Code, passing off, is the one that's most used by the RCMP when they press charges by the crown. The problem with the passing-off section is that to be liable you have to be knowingly passing off counterfeits as original or genuine. If you claim ignorance, then that section doesn't catch you because you can say you didn't know it was a fake.
On the other hand, if the buyer knows it's a fake and the seller knows it's a fake, it's not passing off. It's perfectly fine because they're both dealing with the same information. That's only because counterfeit is not defined as a crime at all, so passing off cannot apply. The buyer knew he was buying a fake, so it's not passing off.