If your rating is within the set limits you enter a tournament. If your rating rises or falls to outside the limits before the tournament starts you are not withdrawn. It would be a bit of a nightmare for admin otherwise.
This player's rating rose sharply, so I guess he became eligible for each band in quick succession. Nothing to be done about it, but it's odd that his rating plummeted so quickly and then rose again equally quickly. There have been many instances of this for various reasons, some of them reasonable, some not.