I read the [rules of implicit bounty award in the help](https://stackoverflow.com/help/bounty):

> 
> If you do not award your bounty within 7 days (plus the grace period),
>  the highest voted answer created after the bounty started with at
>  least 2 upvotes will be awarded half the bounty amount. If there's no
>  answer meeting that criteria, the bounty is not awarded to anyone.
> 
> 
> If the bounty was started by the question owner, and the question
>  owner accepts an answer during the bounty period, and the bounty
>  expires without an explicit award – we assume the bounty owner liked
>  the answer they accepted and award it the full bounty amount at the
>  time of bounty expiration.
> 
> 
> 

However they leave questions open:

1. What if the owner of highest voted answer is the person who offered the bounty, and there are no other answers with >= 2 votes?
2. What if the accepted answer has less votes than some other answer?
3. What if the accepted answer belongs to the person who offered the bounty?

I think the help should be updated to cover the answers, i.e. to explicitly state the priorities and relationships between the rules.