Most of us tuned in to the Xbox One reveal on Tuesday night. Being a live conference, anything can go wrong. So it's almost acceptable that 90% of the voice commands during the Xbox One reveal weren't performed based on what what Yusuf Mehdi was saying. Look at the IGN video below (skip to 1:39:00 or click here) and notice that anytime Yusuf begins talking about an Xbox One voice command, his left hand automatically goes into his pocket, presumably to press a clicker to proceed to a new slide or something similar (unless he's playing one-handed ping-pong if you know what I mean).

(cheers to @taimoorh for the tip!)