I've not had much to do with bounties (though I've read the bounty docs), and would like to understand better...
The following question that I once asked How to disable default alt-left / alt-right keyboard shortcuts for Numbers.app had a bounty applied after quite some time with the note that the answers were 'no longer correct' or 'out of date' (sorry can't remember the wording), so I added an updated answer.
This question on meta seems relevant: Bounty expired without good answers, so did some digging and found the correct answer. Now what?, but in my case, I added a new answer in response to the bounty. I would have thought the bounty would have been auto awarded.
I saw the bounty expire, but can't see it having been awarded to either of the answers. Can someone explain the process here?