When the video cuts away to Josh at :47 and then cuts back to the front of the room, the football has already been switched to cake. You can tell from the seam of the ball.
He's a master of slight of hand.
He's also a master of research. He probably found a player with kids who had recently been to Disney for their birthday. Then it was easy to ask the open ended question, "who has kids" and select the player they had already pegged to get the Disney answer...
As for the pin, Knox / Groot, that's insane.