When Eddie storms out of the locker room, he leaves without closing his locker. In the long shot of Waldo getting towels thrown at him, the locker is suddenly closed.
When Urkel tells Eddie he's proud of him for standing up to Jerry, a towel disappears from Urkel's shoulder between shots, then suddenly reappears when Waldo and Weasel come after them with towels.
When Urkel runs around towel-whipping the guys, it can be seen he is wearing boxer shorts under the towel around his waist, even though he's supposed to have just come from the shower.
When Steve is ironing his clothes in the locker room, the boom mic can be seen for a moment.
When Carl and Eddie are speaking in the living room, and Carl sits down, the boom mic appears for a moment.
When Carl and Harriette are speaking in the living room, and both of them stand up, the boom mic appears for a moment.