Yesterday, I put a 100-rep bounty on an answer in order to give association bonus and network flair rights to our newly-appointed community manager, Cesar M.
While awarding the bounty, I clicked the button, then clicked OK on the dialog. The page refreshed, but nothing appeared to have happened. I tried again, clicked through the dialog, and it appeared as if the bounty was awarded.
I then saw something weird: my name was showing up twice on the bounty tooltip, despite my only having started one bounty. Also, Cesar's reputation page shows two separate +100 bounty gains within seconds, each corresponding to the same bounty, and the revision history of that answer shows two "bounty ended" events. Effectively, I was able to award the same bounty twice to the same user by (unintentionally) exploiting a race condition.
Can there be some extra checking to make sure that the bounty isn't awarded twice, so that one can't intentionally exploit this race condition? Can we also delete extraneous bounty votes corresponding to when this race condition was exploited, both intentionally and unintentionally?