Ok so we all know he runs off, maybe we even all remember using a hunter pet pull, well, here's the new way to do it.
You get 3 party members log out on on top of where he spawns, get the left over people at the start of the instance to reset the instance, get the people that logged out to login, you invite then back, and magistrate spawns back, you pull him and can keep farming him over and over and not pull extra mobs.