If you flag something by mistake, you can 'unflag' it. The 'flag' link turns into an 'unflag' link. I believe there is a time-limit on how long you have the ab

If you flag something by mistake, you can 'unflag' it. The 'flag' link turns into an 'unflag' link. I believe there is a time-limit on how long you have the ability to 'unflag' something. I believe the time limit is similar to being able to edit or delete your comments for a 2 hour period after you made them.