Visible crew/equipment: In the apartment scene with Dustin Hoffman and Valerie Perrine, he prances in front of a vanity mirror, and a big boom microphone is right over his head, hanging deep into the shot, reflected in the mirror. The boom microphone is quickly retracted, so they knew they had made a mistake, but the shot remained in the finished film.
Audio problem: As McQ is attempting to escape from the hoods by driving down the beach in a 4-door automatic Belvedere, you can hear manual transmission upshifts occurring.
Continuity mistake: When Buster and Billie are at Slim Mim's Jamboree near the end of the film, Buster is wearing an open-collar shirt. When they step outside to get some air, it changes to a button-down shirt and tie.
Continuity mistake: Nini's mother fishes the telephone out of the bathtub. A naked little boy prances around the room and Christian De Sica is in a quite recognizable position, leg up scrubbing the sole of his foot. Cut, and De Sica is now simply sitting in the tub as if nothing happened. (00:22:00)
Continuity mistake: Gene Hackman returns a second cookie to Harrison Ford's dish that he hadn't taken - or perhaps it's the same cookie he picked up and returned a moment earlier. Either way, the cookie had suddenly appeared in Hackman's hands going from one shot to another. (00:30:35)
Continuity mistake: In the opening scene, Irwin Ingham's big scarf is wrapped around his neck in ever-changing fashion as it can be spotted looking at the striped area being at different height each time. (00:03:40)