In the beginning of the movie, there are plenty of shots of the orange couch in Gordan's apartment. Later throughout the movie, several cushions can be seen wrapped in duct tape, this is due to the dog playing Agent 11 having torn up the cushions while the camera was off according to commentary.
Michael Clarke Duncan filmed two scenes with a broken leg. The scene where he takes Spot away from Gordon and James and the scene where Spot decides to stay with Gordon and James. Any shots of him standing up was a stand-in.