Normally, Brainstorm was pretty attentive of his lab. He knew well enough when someone was sneaking him in.

Exactly why he squawks when Spinister pushes him. He flails in surprise, just barely keeping his grip on the bow as his arms wave and his wings flap. He curls slightly up mainly by reflex as he swings, but the suspensions keep him secure and his legs and waist firmly trapped in place.