Continuity mistake: When we see Erin and Leah for the first time, they're talking and smoochin'. Despite the conversation being continuous, the reciprocal position of their hands changes abruptly between shots at the beginning (Erin's hand is on the outside of Leah's, then on the inside, then outside again). (00:05:25)
Visible crew/equipment: Ali's assistant sits in her office as she goes to apologise to him. But in the reflection of his glasses you can see the green screen which I suppose is meant be the windows of the office. (01:32:00)
Continuity mistake: The inspector is showing the singer the gruesome images of her friend. As he says "It's how we identified the remains", she raises her right hand, but in the next shot it's with the left hand that she's touching her lips. (00:04:45)
Continuity mistake: Young Theo Decker is having his first dinner with the Barbours. Seeing that he's not eating much, Nicole Kidman asks him if he would like her to ask the maid Etta to make something else. On Theo's right, Andy is holding the fork with his right hand. As Theo answers "I'm not hungry", Andy's left hand suddenly is on the table too. (00:06:00)
Character mistake: The Mother gave the Man (as Panda the cat) a bowl of vanilla ice cream with whipped cream and apparently some chocolate syrup. Chocolate is toxic to cats and most cats are lactose-intolerant. A mature/adult person should be aware that "people food", in general, is not healthy for cats and certain foods (chocolate and cow's milk) are particularly bad and possibly fatal. (00:27:27)
Suggested correction: This situation is actually more complicated in that the mother was seeing the man (her dead grandson), so wasn't really giving Panda the cat the ice cream. What can't be known is whether Panda as the man could eat ice cream with chocolate syrup and not get sick (e.g, vomit) after he turned back into a cat the same day.
Continuity mistake: When Santa tells Noelle he's anxious about inheriting his dad's role, the position of his arms is inconsistent between front and side shots.
Factual error: Most of the action is set in 1988. The prologue with the two little girls is set before or during that year, but the girl scouts are selling "Thindulgent Sandwich cookies", by Sheila G, a brand established after 1992. (00:01:55)
Factual error: The Sheriff of the small town is wearing Sergeant stripes on her shoulder sleeves. If she was a Sheriff then no chevrons should be on her sleeves.
Continuity mistake: In the sequence with the pigeon that tries to topple the severed hand off the gutter, twigs are right next to its fingers or not, depending from the angle. (00:06:35)
Continuity mistake: Andrei is mentally rehearsing icebreaker lines for his first approach to Ramona. Fake macho Silviu sits by him and puts a blunt in front of him, practically under his nose. Reverse shot, and it's gone. (00:02:00)
Other mistake: The opening (like most of the movie) does not make much sense, so you can pick your kind of mistake here; the special effects are cartoonishly bad throughout the big firework explosions. When John Abraham is knocked through a window by a rocket (which takes off with a 270° turn without even rising) to the face, he gets up unscathed and starts screaming for Junky and Chandu. The camera moves from them to him and he's running with the girl in the red costume in front of him (which was way behind, safely, when he crashed through the window, so already that is wrong), and then there's a wider shot. In that shot, you can tell that Adams is bumping into the same people as before and the distances between the extras are all wrong. (00:06:35)
Revealing mistake: Obvious use of green screen for buildings across the street. On and off, the background fades, and buildings appear higher or lower depending on the camera's angle. At one point, the angle of walls behind Rex (Bruce Willis) is at a downward angle, and his head is almost touching the ceiling. (00:06:10 - 00:07:25)
Audio problem: The FBI agent is in pursuit of a suspect in a hospital, once he enters the stairwell he draws his Glock handgun, and a click can be heard for a safety disengaging. Glocks are striker fired, they contain no external safeties that can be manipulated that would cause a sound. A sound can also be heard after the gun is already drawn from the holster, representing a holster draw sound. (00:22:22)
Continuity mistake: Sira pours Sprite into a glass until it is about three-fourths full, but the glass is closer to half-full when he hands it to his mother. (00:02:00)
Other mistake: The Burglar (while tied to a chair and talking about "My Darling Clementine") says, "Apex of Ford's art, you feel me?" Vikar (James Franco) responds, "I feel you." The movie starts in 1969, but rapper E-40 (Earl Tyrone Stevens, Sr.) - "slang master" - supposedly created the expression "you feel me" in the early 1990s. (00:19:53)
Continuity mistake: The girl and guy are in a hotel room and she kisses him good bye. You see her go out of the door and the door handle is on the left side and no chain hanging. Then when you see the door a few seconds later the door handle is on the right and the chain is latched.
Visible crew/equipment: As the camera moves forward in the opening shot, a clear reflection of a film light can be seen on the side of the fire engine.
Continuity mistake: The dorky protagonist just bumped into the bike shop girl. She tells him "It's all good, man", to which he replies asking how's the bike. Behind him, a woman with a dog makes her appearance. Over 10 seconds of conversation pass, and the woman is still where she was, but in the shot that follows, when she says "I'm Cate, by the way", the woman warped past him, and is now behind her to the opposite end of the sidewalk. (00:07:15)
Continuity mistake: When Samar leads Ryan into the lab at the beginning of the film, the door closes almost all the way. However, when the scene cuts inside the lab, the door is suddenly almost all the way open again, and closes a second time.
Continuity mistake: When Aunt Sarah arrives, she dumps her luggage in the hands of Jim and then passes him to his right, leaving him between herself and the door. In the reverse shot, Jim is on the opposite side. (00:29:15)