They're starting with a legitimate product going through a legitimate market. Where we're dealing with counterfeit products, there's no legitimate market for a counterfeit product. Counterfeiters don't keep any types of records. So who knows where it's manufactured at the end? When you do catch the mid-level players in Canada, they're never going to turn on their larger brothers in other countries and things like that, especially in a complex network.
If you're talking about grey market items coming into the legitimate chain, then you can probably trace them back. But for a counterfeit product, it has no business in any market, so there's no way you could possibly track it unless it had legitimate components.