Revealing mistake: During the Yule Ball there is a shot of Professor Moody sitting on a bench tapping time with the music. One can easily see a green object beneath the bench. It is apparent that a hole was cut in the cushion with his real leg hanging below the bench covered with a green leg and foot sleeve. The large green object is his foot with a red dot on his toe. In post production the actor's real leg and foot is to be removed digitally via green screen-like technology and replaced with a digitized artificial one. The red dots are to help coordinate the movements and position of the artificial leg with the actor's real one. This shot obviously got missed by the postproduction team. If you look closely you can also just make out his knee peeking below the fringe of the bench. (01:18:50)