"I would have hoped that dealers at the convention would be honoring this code. I would hope that those who can't even follow our code of ethics at the convention of all places will not be invited back."

Pete; Aren't you putting the horse before the cart? I would think that an official complaint be lodged first, stating all the details and names, and then the seller must be given an opportunity to give his side of the story or make restitution before any action can be taken. A post on a public bulletin board simply doesn't cut it in my opinion.
Regards, Archie