Quote Originally Posted by Alhanelem View Post
[...]If a GM determines that a group is taking an unreasonable amount of time or has not made much/any progress, they will give another group the green light to go ahead and take it.
There you go, you solved your side of the debate on zombie'ing. Which is not the problem being presented in this thread.

As for what's actually being presented, leaving the monster claimed to the group until everyone is dead is a good solution. If they take long enough to rage the mob then that solution is enacted forcefully on the players.