I thought it was a lame approach by the Goober. Kind of like sneaking up on someone loaded for bear and when he's discovered he says 'BOO'.
Alito may have been thinking, is he friend or foe? Not too smart for the Goober.
Alito kept his composure, as he was required to do. The tension followed by relief was too much for his wife who had to listen to the attacks on her husband through out the day.