I remember getting an offer accepted, after several hours, at the very moment another board member (hey Jeff) hit the BIN. Fortunately, the buyer took my offer and Jeff's BIN wouldn't register as it was a millisecond too late.
The card was a super rare 1921 Ruth Barnstorming card, sold a few years ago at the National for an offer I couldn't refuse.
I don't have an immediate opinion on the question at hand however, if there is an obligation it should be adhered to, generally speaking. Now, if a seller didn't set it, and the system does, then I don't know. I guess someone could make another offer and you can accept it. That is within the rules....
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