Plot hole: Mr. Cranston asks Denise to be the accompanist for the school's production of "Chicago". This is an error. In the year 2009, in which the film is set, this would be impossible since the licensing company which has the theatrical rights for "Chicago" restricts the show from being produced (even by amateur groups and schools) anywhere in the greater New York area while there is an open-ended production running on Broadway.
Factual error: The part of the movie where they have had the morning updates at the police station, Richard Gere later walks on the sidewalk and stares deliberately at a pair of Muslims praying. The sun is shining on the backs of the Muslims heads indicating that they are facing west even though Mecca would be off to a much more easterly direction from Brooklyn.
Continuity mistake: From behind, Gigi points her gun forward, but from the immediate front angle she is moving it backwards.
Factual error: At 01:29:08 we see Carys lying despondent on the couch in her living room surrounded by balled up tissues, empty food containers/soda cans and trash - all the signs of going through a bad break up. She gets up to answer the door for her mom, who has brought by a plate of cookies. Carys sits on the couch again, looks down, looks up, and by 1:29:40 the entire room is clean; we see her mom fluffing a pillow. There is no way her mom could have cleaned the living room in less than 32 seconds.
Continuity mistake: After the blue car hits the white car, the back bumper, on the left side is sticking up. In the next shot of the white car from the back, the bumper looks like nothing happened. (01:01:30)
Factual error: When Esposito revisits the murder scene, he asks Morales whether he would prefer the culprit to receive the death penalty. Morales answers that he would not, claiming that to doze off and fall asleep (hinting at execution by lethal injection) would be too good for the man who raped and brutally murdered his wife. Execution by injection has never been practiced in Argentina - where the last execution was carried out in 1916, by shooting - and was legally enacted only in 1977 and practiced the first time in 1982 (in both cases by the state of Texas). Thus, it seems anachronistic that anyone would equate the method with capital punishment in 1974, when the scene is set. (00:24:00)
Continuity mistake: When the family is in a parking lot, the amount of beer in the glass on the car's rooftop keeps changing between shots.
Continuity mistake: After seeing the aborted baby, Quaid goes into the bathroom and plunges his head into water. His hair, however, is perfectly dried afterward. (00:35:35)
Continuity mistake: When Lex Luthor has his battle suit on and fighting Superman and Batman, the head and neck piece change dramatically and constantly. Sometimes the piece surrounds his head, leaving plenty of room and sometimes his head sticks out over the piece. And it's not a matter of angles, because in some shots, everything being the same, the side piece remains at ear level and his head is either above or below the head piece.
Revealing mistake: When Mr Goodall is attacking the bloke near the start, he is supposed to be hitting the other man really hard, but doesn't come close to hitting him.
Continuity mistake: When Billy and Bolger are driving down the road after the funeral, they are on a 2-lane road, with nothing but grass and trees on either side. But when the shot changes so they're facing the camera, it's a 4-lane road with a lot more traffic. Then the road becomes much bigger with a median.
Continuity mistake: After Paul tells Meryl that he was hesitant about adoption during their jogging, Meryl returns home. While jogging, she was wearing very tight grey pants. At the barn, her pants are a lot looser.
Continuity mistake: The concierge is trying to come up with a written answer to Mr. Ozu's Anna Karenina. She crumples the first sheet and there's a cut when she tosses it away; the pad changed position and all the other discarded messages are scattered differently between shots. (00:31:30)
Continuity mistake: When Mary first opens the phone book at the post office she lands on Finklestein but when she puts her finger on the name she chooses it as Hororwitz, even though she never turned the page again.
Continuity mistake: In a "movie inside the movie" moment, Arshad Warsi is on the witness stand. In the wide shot the hand he had on the book is held up gesticulating, and at the end of the shot he has his hat in both hands, while it is under his armpit in the shots from the front. (00:12:55)
Plot hole: Every ghost that we see in the house looks the way they did when they died, for example the girl from the film's intro is seen without skin on her face, which happened to her before she died. However, in the final scene when we see Simon's ghost joining them, he looks completely normal, when he should have had a throat slit wound and the carved markings on his skin. (01:31:20)
Factual error: In the dinner scene with Helen Mirren and James MacAvoy, she was playing a gramophone recording of "Un Bel Di" from 'Madame Butterfly,' and the year was 1910. The opera was not recorded until much later.
Continuity mistake: When Pierce Brosnan is first in the classroom, the writing on the blackboard keeps changing.
Continuity mistake: Sophie Marceau's Jeanne meets the Hachette executive Robert (Didier Flamand). She enters the room with handbag and jacket in one hand. She then follows him into the other half of the room. Now she has her clothes in her right hand and her bag is in her left. Not just that; the man had the folder in his left hand in the first shot, but in the new one it's in his right. (00:04:25)
Continuity mistake: Mulan tricks her father into taking his medicine, and everyone has a laugh at him. Between shots she is pouring from the teapot first with the right, then the left, and one of the geezers sitting by is cackling with a different posture and hands switched as well. (00:05:10)