I think this question's [revisions][1] and [timeline][2] may reveal a bug in the bounty system.

The timeline summary as I see it is:

 - Question asked Mar 17
 - Answer added Mar 18
 - Question edited (extended) and bounty added Mar 20 
 - Answer edited and accepted Mar 21

This was the only answer to the question.  From [this answer][3]

> If the bounty starter accepted an answer during the bounty period, that answer is awarded the bounty.

This appears to be the case here, so I'd expect the bounty to be awarded.  Is this a bug in the bounty system?

I'm not too fussed about the actual bounty here (I'd answered the question before the bounty was offered anyway), it's just that it'd be good to either fix the bug or improve the documentation I guess.

[1]: http://stackoverflow.com/posts/15461556/revisions
[2]: http://stackoverflow.com/posts/15461556/timeline
[3]: http://meta.stackoverflow.com/a/16067/150208