Continuity mistake: When the form falls onto the girl's face, the position of the form changes between shots. (00:00:35)
Character mistake: It's said in the movie a vice presidential candidate never gave a concession speech. Geraldine Ferraro did this in 1984.
Continuity mistake: Tom walks into Anthony's memory. Anthony is sitting by the pool next to a table with two glasses of beer, which are 1/3rd empty. A few minutes later the memory is replayed, but this time both beer glasses are mostly full. (00:49:50 - 00:58:35)
Character mistake: When Michael goes to the antique shop, the sign out front is spelled wrong; it reads "anitques."
Continuity mistake: When the dog comes in and takes Dale's hand the blonde woman's legs keep changing position. (00:47:00)
Continuity mistake: Dinner at Forestier's home, and Georges Duroy does not know which knife to use to eat. The asparagi in his plate are across the small pie in the wide shot, and in close-up they are arranged entirely on the side without his intervention. (00:08:20)
Plot hole: The killer has been living in the (apparently big enough) crawlspace between walls and floors, for over a decade. There is no explanation (or rationale) given on how he moved the various objects inside every room, closed doors, fed when the house was not occupied, hid the various corpses and, silly detail, concealed his own BO and the stench of his own living quarters, which is something hinted at when they find out his hideout. It is explicitly said that he is agoraphobic and does not get out, ever.
Other mistake: Aladdin slices off one head of the monster in the tomb. The body spurts copious amounts of blood and the severed head even bounces on him repeatedly, but Aladdin's shirt is immaculate afterwards. (00:04:40)
Continuity mistake: George's son is disappointed because his dad missed the ball game and tells him that he should have been there. Meanwhile Denise Richards approaches the cooking pot with her spoon in her right hand and the plate in her left. Close-up on her telling Howie that dad was busy, and spoon and plate switched hands. (00:18:45)
Continuity mistake: When Jeremy and the cop girl are shooting for practice, the amount of cans changes between shots.
Continuity mistake: In the intro, the mother is playing with her kid; notice that when she grabs the gladiator puppet she is holding it with the index finger above the shoulder in the wider angle, below in the frontal close-up. (00:01:00)
Continuity mistake: When Eddie Murphy's assistant makes assumptions about why Jack isn't speaking, he throws his notepad down and has empty hands as Jack pushes him out of the office. When the angle changes, he has a notepad in his right hand.
Other mistake: After the daughter visited with her mother for the first time, she is reviewing the footage with the priests. No such camera angles were taken for what they reviewed, only an overhead room camera would have been available.
Visible crew/equipment: When the 2 bad guys get the car you can see the 2 cameramen reflected in the car door. (01:10:00)
Factual error: The movie changes between a basketball season and a playoff basketball game then to a baseball game being played in what looks like early summer...back to a team getting ready for the basketball playoffs. The two seasons don't overlap.
Factual error: When the underground garage of the market is flooded, the car that Kyle and Heather are in does not flood. A car is not water tight like a submarine. Even though the water does not cover the top of the car, water would flood the entire car within minutes.
Continuity mistake: Wren is asking her mother about the form for the college loan. When she remarks sarcastically "Afghan citizenship, hello?" she has a big bunch of hair in front of her shoulder, as opposed to the previous shot. (00:02:30)
Factual error: The Iowa is sailing with a depleted crew, one that most likely has no experienced gunner's mates. The 16-inch turret requires a 79-man crew to operate it, and can fire a salvo every 30 seconds. Despite these handicaps, the minimal crew in the movie was firing salvos every few seconds.
Continuity mistake: In the car after Martin tells Hans about the throat slitting story, Billy and him get into an argument about the violence of the story. Billy says "It's going to be violent, it's about seven fucking psychopaths!" Martin then says "Hey!" But you can see in the back seat his mouth doesn't move for that. Then it cuts to a close up of Martin and his head is in a different position, facing Billy where he was looking out the window a moment before. (00:58:05)
Continuity mistake: When Sheriff Cooper writes "Karsson" and underlines it on the chalkboard, the way it is written changes between shots. In one particular shot, the line he underlined it with is suddenly rubbed out.