First two minutes of that video states the issue is limited to the case where the agent represents both the buying and selling parties which is only legal in canada.
I'm not canadian. I dont know how commonplace this is. But as an american it sounds pretty foolish of someone to accept a deal on your next mortgage with someone who openly controls both parties.
Double-ended deals are legal in some US states e.g. California, and they are indeed an opportunity for breach of fiduciary duty. The way it works is that a crooked agent would get the seller to sign a listing contract that stipulates 3% to whatever agent represents the buyer irrespective of who that agent was working for. Then present only double-ended offers, or lowball outside offers to the seller -- hiding any higher offers that came through buyer's agents. And naive sellers have been defrauded this way.
The seller's defense is simple: Refuse to sign any listing contract that stipulates more than a 1% commission to a buyer's agent that is in any financial way affiliated with the listing agent's office. 1% being roughly in line with the actual effort required from the listing agent to deal with buyer-side coordination as well.
Such a stipulation doesn't quite close the door on collusion through favor trading, among agents in the local old-boy-and-girl network. But it's enough to shield you the seller from the grosser frauds out there.
I'm not canadian. I dont know how commonplace this is. But as an american it sounds pretty foolish of someone to accept a deal on your next mortgage with someone who openly controls both parties.