Also, this brings up some interesting questions about Hibram. He activates Magic Mirror when he is in Melee range. So a party planning to kill him with ranged magic would be screwed if someone from another party wanted to try to melee him to death. Is the second (melee) party at fault? What if they had truly planned to kill him with melee attacks? They're clearly, then, NOT just doing it to prevent competition...so where does this ruling sit on that?
There are other similar situations where legit strategies seem to preclude other options - who has the right of way? If my party, as the dominating party, uses a very specific strategy that many common strategies would "ruin" then can I report the people ruining it?