I’m not a lawyer or a realtor, but I can’t see how you owe this guy anything at all. I agree that if he had worked hard for you and things just didn’t work out that it might be nice to throw $500-$1000 his way, but with his current attitude I wouldn’t give him the time of day much less any money.

I met with an agent once who said that he required all of his buying clients to sign an agreement that he gets full commission on any property that he showed me. In this day of Redfin and Realtor.com, if the only value that an agent brings to a deal is finding me properties, and wants me to sign something that guarantees his commission, then that agent clearly has little to offer. I moved on.