Continuity mistake: In the scene where Alec Baldwin and Demi Moore are in the car and he's threatening to run over her son, who is riding a bike in front of them, Alec swerves at the last minute, and Demi looks over her right shoulder and collapses in relief, but in the next shot, she's looking over her left shoulder, collapsed in relief. (00:48:40)
Continuity mistake: In the final underground laboratory explosion scene Keanu Reeves and Rachel Weisz are being pulled up to the surface in a cage by a crane on the surface and are covered with grey soot from the underground explosion. In the ensuing scene when being met by the people on the surface they are all cleaned up.
Continuity mistake: John Smith's guns can hold about six dozen bullets apiece.
Continuity mistake: When William Petersen is on a cordless phone at work, he says "the guy gives me the creeps and the girl is my daughter." As he does, the phone cord appears, and the phone's position changes as he hangs it up.
Continuity mistake: During the night scene when the cop is shot, the cigarette in Peter Stormare's mouth switches between being long and nearly consumed. (00:28:52)
Continuity mistake: In the final battle scene between Geena Davis and Craig Beirko, Beirko's character slashes Davis' character across the stomach (upper right hand side). In the next shot, the wound is located on the lower left side and in a subsequent shot, the wound has multiplied to become two wounds: one in the upper right hand side and a second in the lower left hand side.
Continuity mistake: When Campbell and Cole are inside the Chinese herbal-like shop, the woman behind the counter offers Campbell a drink. When he goes to drink it he holds the cup with two hands but in the following shot he's holding it with only his right hand. (00:14:05)
Continuity mistake: Early in the film, Michael talks to Harry Boland on a boat. During this scene, a cigarette appears in Boland's mouth that was not in the previous shot. (00:40:40)
Continuity mistake: When the press secretary kisses the hand of the alien-dressed-as-a-seductive-woman, the eyeball ring is on her right middle finger but after she knocks him out (or kills him) the ring is on the finger between the middle and the pinkie. In subsequent scenes it's back on the middle finger. (01:01:35 - 01:04:20)
Continuity mistake: When Mrs. Waterhouse walks into the livingroom and greets her three babies, there is a large area rug in front of the coffee table. However, as the babies fly towards her in the wide shot facing her, that area rug is gone! (00:22:55 - 00:23:50)
Continuity mistake: Near the end of the film, as Aaron/Roy reveals his deception to Martin, notice the jail cell 'door' behind Martin. During the majority of the scene the door is closed, but in a couple of shots it is wide open.
Continuity mistake: There is a scene where Al Pacino is getting dressed for a dinner while talking to one of his aids. He addresses the aide and is seen in a dressing gown with his hair all tousled and untidy. He turns away from the camera, looks in the mirror, and turns back to camera. Miraculously his hair is now tidy as can be, with not a hair out of place!
Continuity mistake: When Shale gets in the fight in the library, he takes a round to the upper left chest. When he takes the shirt off to reveal the vest there's no bullet and no damage to the vest.
Continuity mistake: Montgomery's shirt, when he is ripping pages out of a book, is blue. However, when Azazello takes the gun from his hunting vest, his shirt is white.
Continuity mistake: There is one scene at a party where a guy drives off in a car. When he gets into the car, it is facing up the driveway with another car in front of it. When he drives off he drives straight ahead, without reversing down the driveway.
Continuity mistake: When Demi Moore just finishes her dance for Congressman Dilbeck, he helps her put on her blouse. When he puts it on, her hair is underneath the blouse, then a little bit later, you look again and her hair is above the blouse. (01:19:07)
Continuity mistake: When Billy finds his old friend outside of the hotel, he has a grey sweater on. Then when they go into the hotel room, his sweater is green.
Continuity mistake: In one scene, Zane disturbs a lecture on terraforming at JPL and gets thrown out by security guards. Later on in the movie, somewhere in a Mexican bar, Zane and Ilana are discussing global warming. In a flashback Zane remembers the lecture at JPL. Strange thing, however, he can even remember a part of the lecture which was given at a time when he had already been thrown out.
Continuity mistake: When Jessica confronts Dr. Fenistone in the doorway, which shoulder her ponytail hangs over changes between shots through the scene. (00:55:55)
Continuity mistake: When James first meet Helen and Vaughn in the hospital, Helen starts to walk away while Vaughn is examining James' scars. You can see that Helen is almost at the other end of the corridor but when Vaughn finishes examining James, he walks towards Helen who is only a few meters in front of him.