Continuity mistake: When DeVries is being chased by the cops, he passes some roadworks. At first there is only one wooden barrier in his way, with a workman about to position another one. The next shot shows two in place. DeVries appears to knock these over, but in the following shot he only hits one, with the other one transported to his left, ready for the cops to knock over. (00:03:10)
Continuity mistake: When DeVries is speeding through the park, he drives over a small ramp. In the first shot, the pathway is perfectly clear, then in the next shot some debris and rubbish have appeared. There is also a green barrel that moves from the grass bank on his left to his right side. (00:04:45)
Continuity mistake: When DeVries runs through a sheet of glass killing two workmen, a large bloodstain appears on the windscreen. When he speeds up before the police roadblock however, it's almost disappeared. When the cops start shooting, it's back. (00:05:35)
Continuity mistake: Shortly before DeVries encounters the police roadblock, he emerges over a hill, closely followed by two police cars. When the shot cuts to the roadblock then back to DeVries, no police cars are visible out his rear window. (00:06:45)
Continuity mistake: When DeVries' Ferrari crashes into the fence, the license plate is lying crooked, touching the bumper. When the cops blow it up, it's not touching the bumper. Also notice that the petrol tank and exhausts have been removed, revealing that the car blows up by explosives rather than police gunfire. (00:07:40)
Continuity mistake: When DeVries gets out of the Ferrari covered in blood, Willis is seen pointing a pistol at him. When the police blow up the car, he is using a shotgun. In fact, when they blow up the car, most of the images used are the same shots of them firing at the car before it hit the roadblock, only they're flipped. Willis also appears to switch from a right handed shooting stance with the pistol to a left handed shooting stance with the shotgun. (00:07:45)
Continuity mistake: When DeVries gets out the car and laughs at the police, he is seen facing them. When the car explodes and blows him off his feet, however, he has his back to them. (00:07:55)
Continuity mistake: When Miller kills the record store owner with a baton, he's seen with his head about a foot away from the left record racks. When Beck finds him, however, he's lying at a totally different position and angle. (00:15:30)
Continuity mistake: The guy in the white suit at the Ferrari dealership is shot dead by Miller, but he reappears at the strip club. He's the one shaking hands with customers at the dance floor. (00:25:15 - 00:42:00)
Continuity mistake: When Miller is eying up the red Ferrari and he opens the door, two mechanics wearing green overalls appear behind him that weren't there in the previous shot, and you can see that the car they are looking at is now covered by a shadow. (00:25:35)
Continuity mistake: When the Ferrari boss calls Eddie to help deal with Miller, two guys wearing suits are standing in the sunshine next to a grey car. When Miller refuses to take no for an answer after being thrown out, you can see that the guys are gone and the car is now covered by a shadow. The red Ferrari also now has a longer shadow. (00:26:15)
Continuity mistake: When the two cops pull the stripper over, their car stops in the middle of the road. When Beck and Gallagher pass them later, however, their car is closer to the pavement. Their car moves yet again when Beck looks back at them out of his window. Also notice that three headlights are now on, including one that the stripper blew out. (00:51:30)
Continuity mistake: When Beck and Gallagher are chasing the stripper (Claudia Christian) Gallagher shoots out the wheel of the stripper's car, which then proceeds to crash into a mannequin warehouse. As Beck and Gallagher approach the suspect's car there is the head and hair of a mannequin showing out the broken back window. Obviously from when Claudia Christian crashed into the warehouse. However the front car windscreen is unbroken as Beck passes it. So how did the mannequin enter the car? (00:54:20)
Continuity mistake: When the stripper throws herself off the building, she's seen lying at a totally different angle from where she should have landed. Also, when the dog finds her, her head is lying on a metal strip on the pavement, which disappears in the next shot. (01:00:00)
Continuity mistake: When the cops find Beck with gunshot wounds in his stomach, the amount of blood on his shirt increases substantially between shots. (01:24:15)
Plot hole: When Gallagher is trying to kill the senator at the end, he is fired on by his bodyguards. Yet when they finally catch up with him, they're quite content to stand back and watch him torch the senator. One of them even lowers his gun. They couldn't have known Gallagher and the senator were aliens. (01:27:20)
Other mistake: During one of the early investigations of the murder in the record store, there is a scene of the FBI agent and the detective in a Porsche driving through an intersection, almost crashing into a yellow car entering the intersection and swerving away to avoid an accident. Later on in the movie, there is another scene of the Porsche going through the same intersection, at a different angle, and almost hitting, again, the same yellow car, at the same position, doing the same manuever to avoid a crash.
Continuity mistake: Detective Beck is shot by the stripper on the rooftop. He jerks to the right. Yet later it turns out he was shot on the left shoulder. If he was shot there, he would have jerked to the left.
