If the offer "as was" was accepted by the homeoner, then they cannot, after the offer is accepted, alter the terms. The question is, whether the offer was in fact accepted. If before the seller has indicated acceptance of the offer they sent you a list of exclusions in response to your offer, that constitutes rejection of the initial offer and the return of a counteroffer; they would therefore not be bound by the original offer you made. So what matters is the timing of when they accepted vs. when they sent the amended list of exclusions. They are bound to any offer they accepted prior to sending you a counter. Note that while the bank's approval is important for the seller--it's what lets the short seller off the hook for any remaining balance on the loan--it is not important to the more basic issue of whether the offer was accepted or countered, since the bank is not actually a seller of the home.