Catnip covered the part about how it's possible but I have a bit more I'd like to add. If you know the answer to the question you shouldn't ask it in the first place, and since he seems to have asked then answered in a short amount of time I'd say that's what he did but I couldn't be sure. One thing Catnip said that I think is wrong is that thread posts are exceptions. Not really, as thread posts shouldn't be given BA at all. Another thing you should note is that you ARE allowed to answer your own question and BA it if it has gone for more than a few days without an answer and you learn the asnwer elsewhere in that time. In this case he isn't allowed to do that and should be flagged for it, so yeah.