Factual error: Kathleen Quinlan is named Janet Dunn, but when Gene Wilder looks at the newspaper and sees the headline about her murder, it falsely says her name is Janet Stone.
Continuity mistake: When Kenny Rogers gets trapped in the rest room at the beginning of the film, he pulls the knob out from the door. When this happens, the knob is on the left side of the door from his point of view. After he climbs out the window, the door has changed to having the hinges on that side and the style of the door does not look like it has a knob at all. A rest room this size would only have one door, so it has to be the same door.
Visible crew/equipment: Mr. Preskovitch came to visit Pierre and Thérèse to give "doubitchou" (chocolates). When Mr. Preskovitch said "Vous ne les goûtez pas, Mme. Thérèse?" [You don't want to eat one, Mrs. Thérèse?], a boom mic can be seen in the reflection of the right door, in the top right pane of glass. (00:26:25)
Continuity mistake: Near the beginning when the guy is robbing the liquor store, he's holding his gun with one hand. In the next shot, he's holding it with two hands.
Revealing mistake: Chong arrives at the curbside of the airport. The guy pulls up in a yellow Datsun for him. The fender is already dented. Chong starts throwing the guy into the fender at the exact point of the dent - the fender must've gotten dented in an earlier take.
Continuity mistake: Myra Bruhl is popping pills at the beginning of the movie; when she puts down the container, there's a white-labeled bottle on the bedstand that was not there before. (00:02:40)
Visible crew/equipment: When the plane drops the grenade into Halicki's car, and he throws it through the sunroof, it blows up the car tailing him. In the slow motion shot following, the stuntman's crash helmet is visible. (00:50:00)