...and it's probably slightly bugged so that no matter what you do, if one of the switches is still on then he'll always appear in a chamber for a heal. I say "teleported" but it was definitley bugged out as he dissapeared, he didn't run off or anything, and then I imediately got his healing cut scene.
Actually in my case, it was HIM that was bugged. He did tele to the switches and turned them on, time after time. After about 10 reloads, he finally decided to behave normally and I was able to finish him off in no time.
