A while ago I offered reputation to the first person that could come up with a solution to this problem using Brain-Flak/Brain-Flueue. A user was successful and I created a bounty on the question to award their answer (not visible to lower rep users). The answer has since been deleted because it was not "a serious contender for the winning criteria in use". I don't disagree with the posts deletion, it was not well golfed at all and those are the rules, but now I have a +150 rep bounty sitting on a question to award an answer that no longer exists. At the end of the week the 150 rep will have to go to one of the answers on the challenge. It seems dishonest to award the answer to another answer after stating it was for a specific answer, but I'd rather not let it be awarded to a random answer on the question. What should I do?
I can see three options here.
Wait and hope @DestructibleLemon fixes their answer. They still have 5 days to do so.
Award the bounty to another answer that fulfills the criteria. @Riley's seems to be the fastest valid answer, and that an answer has to be valid to be posted on PPCG, bounty or not, is always implied.
Ask a moderator to refund the bounty, either publicly or via a flag. We would do so for a bounty on a question that should be closed; this situation isn't that different.
What option you choose is up to you.
That said, I'd like to add that "Fastest Gun In The West" bounties, at least ones without any quality thresholds, seem to be a bad idea. They encourage subpar answer for the sake of collecting the bounty, which isn't doing anybody any favors and leads to problems like the one at hand.