I asked a question. I put up a bounty after a period with no answers, and there was only one answer. Nobody else answered, and one person voted this answer up (only one, no downvotes). I voted that answer down, because it was wrong and I did not want it to get my bounty.
When the time came for the bounty to be auto-awarded, it just... disappeared. The bounty was removed from the question and no answer was accepted. I don't know if this was because I downvoted the only answer, or there was no upvoted answer, or something else. Can somebody please explain how this works?
(If you are wondering what question: Android YouTube app Play Video Intent. The other answers were added much afterward the bounty ended.)