Can a buyer's broker owe me any duty even though I'm the seller?

Generally, no meaningful fiduciary duty — a broker representing the buyer owes their loyalty and duty of full disclosure to the buyer, not to you, and you shouldn't assume otherwise just because you're dealing with them courteously through the process. That said, a buyer's broker isn't free to actively mislead you or engage in dishonest conduct; there's a baseline expectation of fair dealing and honesty toward the other side of a transaction that exists separately from the loyalty owed to their own client.

Practically, this means you shouldn't rely on a buyer's broker to look out for your interests, explain terms in your favour, or flag problems with the deal from your perspective — that's not their role, and expecting it can leave you exposed. If you don't have your own broker or lawyer involved, you're effectively negotiating without anyone whose duty runs to you specifically. Given that, having your own representation — a broker if you're using one, and in any case a Treadstone business lawyer reviewing the purchase agreement — matters more, not less, when the other side has professional representation and you don't.