Can a bounty be awarded to an answer in a comment? Recently I have placed a bounty on this question. The question has no answer in technical terms, but it has been answered in a comment within the bounty period. Now the banner below the question says that the question had a bounty from me which ended so-and-so many minutes ago, and it says also "you have 23 hours to award the bounty". \-- Can I actually do this?

No.

The best you can do is what you just did after Michael's suggestion: comment to ask the user to post it as an answer if you would like to award the bounty.