..would have been a confirmation popup, or a rollback to the previous state, given the testiness over popups. The latter idea is probably the "correct" way to do it.
See the UI Hall of Shame for more examples of going astray with user reqs.
You're pretty free with scheduling my time. A rollback? Screw that. The current hack took 5 minutes, removed the problem a lot of users were having, and added significantly useful functionality.