Factual error: Right before Frank humiliates Dorothy for the first time, he blows out one of the gaslights in her apartment. That is never done in real life, for the same reason you would not blow out the pilot in your stove.
Continuity mistake: In the sedan/pickup chase, both of Cobra's headlights are shot out at the start with pinpoint accuracy. A minute later as the cars race down the freeway, the holes where Cobra's headlights used to be are filled with black plastic discs.
Revealing mistake: In the car chase scene where the cop is after Roland, you can see that there is no key in the ignition of the cop's car.
Continuity mistake: During Kevin Bacon's race with fellow messenger, the scenes shift back and forth from New York to San Francisco. In one city, he's on a fixed gear (no freewheel on back wheel) and when the race is taking place in the other city, he's riding a single-speed. Basically, the cityscape and bicycles switch from scene to scene.
Continuity mistake: When Eddie and Michel are in the police station and Losado comes to pick up Michel, her hair clip is on the left side of her hair. After Losado and Michel get into the car, her hair clip moves to the right side.
Revealing mistake: When Lazarus and Klepper's vehicle goes through the wooden crates and flips over, you can see the wooden ramp used to launch the car.
Factual error: Throughout the film, they play one of Strauss' Four Last Songs, which is credited as being "September." The song actually played is "Beim Schlafengehn."
Continuity mistake: When Max and Joey take a picture at Luigi's house, Joey is looking at the camera and not smiling while Max's hand is just below Joey's right ear, getting ready to grab it. When Max makes a copy of the picture later, Joey is looking away from the camera, smiling, and Max's hand is on Joey's shoulder. (00:50:50 - 01:14:40)
Revealing mistake: When Danny DeVito brings home the 'bigger dog' he says for the new dog to go eat the little dog that always bothers him. He lets the dog go and the dog goes after the little one. But when they show the dog chasing the little one he almost runs right past him. There must have been a trainer on the other side of the set calling the dogs to come over because he wasn't chasing the little dog. (00:40:30)
Continuity mistake: In the scene where Remy finally figures out that Ann has some serious questions about his dept., he pushes her against a tree. When the camera is on him, her necklace has swung around to the back of her dress. When the camera is on her, the necklace is 1/2 inside and 1/2 outside the front of her dress. This switches back and forth several times.