Wheatley responds about as well as you would expect--he jumps back, hands (and portal gun) raised in defense, looking like he's on the verge of a panic attack before he realizes that this is another crew member and backs down accordingly.

That does not, however, mean he's necessarily pleased with the turn of events.

"Should watch where you're going," he quips, giving York a clear once-over and seemingly more perturbed with the hallway than anything else. "Turned around, are you?"