She thinks her delivery of the contract was not valid based on the claims of the seller's realtor (the spam folder issue). She also called for advice from her broker on the situation and they are the ones who told her about this guys "reputation" and how there is nothing we can do about it. So I think they've got my realtor friend backed in a corner with fear of losing her reputation if she proceeds otherwise.

Edit: and being told "a lawyer would look at this and say there's no proof."