The situation: Another user posted a (wrong) answer to one of my questions. However, in the comments that followed he gave a "correct answer". I told him that was the answer I was looking for, waited a while, and when he didn't post it as an answer, leaving it in the comments, I posted it as an answer myself and accepted it.
He proceeded to get upset with me, downvotes, etc and the usual.
Regardless, it got me thinking - What is the proper protocol for this situation? Should I have asked him specifically to make a new answer for me to mark? Should I have replaced his answer with the new one, even though that would have invalidated the whole discussion that followed?