Would it be possible to (or do you think there should be) place a grace period on the reversal / removal of a bounty, and (past the grace period) have a time limit on changing the description for the bounty?
Say I create a quesiton in Flex, and nobody's seen it for a week. I may hastily add a bounty with a reason like "To get seen". Whereas moments later I'll realize what I've just posted, and want to re-word it to something like "Increase exposure on the quesiton / incentive for answers." (more professioinal, a complete thought, sounds less like system-gaming.)
Some people are mis-understanding my suggestion. I am suggesting that only the person who has placed the bounty can see the bounty until it is locked in, but after that they are able to change the bounty description / reason within that extended grace period of editing. Complete reversal is locked in once the bounty is visible.