He was in the room. The Scarlet Witch, the most powerful Avenger to ever live RAN instead of defending herself. That means she knew the killer and was afraid to hurt him. It points to an inebriated Nightcrawler. Look, Mystique would want Nightcrawler off the board and in the pit. With Storm on Arrako and Jean in NY, the Spring seats on the council would be empty. The professor and Magneto would have only Kitty Pryde.