Looking at the results of letting US DEA agents run traffic stops in Canada, whatever could go wrong?

I can't find a link, but a few years ago, there was a joint task force in Alberta where US agents trained RCMP officers on the "proper" way to stop drug trafficers. They set up an illegal roadblock, illegally stopped and searched drivers, and illegally arrested someone who complained abut the lack of legality. Said complainer then suffered injuries while resisting arrest. As the complainer turned out to be a local police officer, it made the news.