I agree with the second, the first however I believe in some situations a confirmation can be ideal - delete, de-activate, flag, etc.

Of course the quick unflagging is nice and works - just wondering if it would help with alerts in the back end.

Maybe the logs could be analyzed to see how many "mis-clicks" are triggered daily?

This should be easily do-able since the calls are timestamped and could be compared (only count flag/unflag that is within 20 seconds of each other or something similar?)