While my ls was forming to fight kirin earlier today, a couple members got tells from someone. He is the leader of a JP HNM ls, but that is beside the point. He had 3 fellow ls members with him in the Kirin room, he had followed us from fafnir, and told us he was gonna steal Kirin from us. The conversation went around in circles for a bit, but basically if the mob doesn't kill you after someone steals claim, they have done nothing wrong.
After enough questions and bitching on my part, the GM showed himself to them, and stayed for a short while. At the end of the chat, before we popped Kirin, the GM asked me to go to them, and /say that we did not want their help in any way with our fight, including healing us or helping on summons.
The fight went rather smoothly, and they stayed in the tunnel by the teleporter for most of the fight. The GM left early in our battle, and a couple of them (one a monk, another a pld) ran out a few times and looked around.