Continuity mistake: During one of the scenes when Brad Pitt arrives home, he is driving a Lincoln Town Car, not his Cadillac. This is the car that he doesn't get until later, when he steals it and drives home during the scene when they crash the cars into each other at the end of the driveway.
Suggested correction: Didn't he steal the Lincoln after the restaurant?
He did. But, the car appears before he steals it when he drives home after going to her office.
Continuity mistake: When John and Jane reach home after racing each other from the restaurant and she crashes her car into his, he's wearing a black jacket just before she hits him and no jacket just after. (01:05:15)
Continuity mistake: Near the end, when the Smiths are hiding in the shed, from the inside the front of the shed and the door have several bullet holes (as do the sides), but in the long shot of the shed, the front is in perfect condition. (01:45:00)
Continuity mistake: When the Smiths steal the van from the Coleman's, a cross on a rope is hanging from the rear view mirror. During the BMW chase, the rope goes from being almost a foot long to about two inches long. (01:23:30 - 01:24:40)
Continuity mistake: While being chased by the 3 BMWs, the passenger's headrest of the Dodge minivan driven by Brad changes from a 1-piece (part of the seat), to a headrest that you can adjust the height and it keeps changing during the scene.
Continuity mistake: After the botched hit in Mexico, Jane returns to her office, a little beaten up, and her associates tend to her wounds. Particularly clear is an injury to her right shoulder - it has bled enough to mark her singlet top, and is covered by a large piece of plaster. Yet when she dances with John in the restaurant, only a few hours later, there is no sign of plaster or wound.
Continuity mistake: When John sees the BMW's in the rear view mirror for the first time, the cross hanging from it disappears. (01:24:30)
Continuity mistake: When Jane and John Smith are fighting each other in their house, John Smith is left with several large scratches on his left cheek. Throughout the rest of the movie, his scratches change size, position and shape.
Continuity mistake: The second time John and Jane enter the elevator, they both have machine guns. However, when they exit, Jane is holding a handheld pistol and they have swapped sides. (01:42:00)
Continuity mistake: When John and Jane steal their neighbor's minivan (after their house explodes) and back out the driveway, an assassin jumps onto the back. John hits the brakes and the assassin falls off onto the ground beside the van. In the next shot it is implied that the van runs over the assassin (two bumps), but John has not turned the steering wheel.
Continuity mistake: Near the end of the movie when John and Jane are in the shed and taking off their suit coats, there is no slit or hole in John's right pant leg where, minutes before, it had been punctured by Jane's wayward knife.
Continuity mistake: During the car chase, the wound on John's cheek changes colour between shots. (01:21:55)
Continuity mistake: During the car chase on the freeway, Jane forces one of the pursuing cars off the road by driving, with it, through those large barrels of water near freeway exits. Water cascades over the cars; one interior shot shows that it's virtually impossible to see through the windscreen. Yet in the next shot, a few seconds later, all the cars are completely dry.
Continuity mistake: When John and Jane open the door to greet the neighbours after the fight, Jane is on John's right side under his arm. In the next clip she's on his left side.
Continuity mistake: When Pitt is chasing after Jolie, he crashes through a fence and fires his gun, hitting the car's windshield. To the left of where Pitt is, you'll notice that there's one rail missing in the middle. When he climbs through the fence to the street, the fence rail has returned, and the hole left by Pitt is now slightly wider, just enough for him to climb through. (00:45:40)
Continuity mistake: During the beginning scenes of the car chase, the golf bag moves in the trunk. In the first clip there are some bags in front of it, but in the next it's all the way in the back of the trunk. (01:21:35)
Continuity mistake: During the car chase you see several clips where the car's sides are bumped and have bullet holes, but also several clips where the cars sides are in pristine condition. (01:23:15)
Continuity mistake: When Jane and John are fighting in their house, John runs by and knocks the teapot over. He fumbles with it then grabs it with the top facing him. In the next shot, the top is facing away from him, so that it may proceed to fall off.
Continuity mistake: When Jane enters her house with the girls, the front door has a chain door lock. When John enters with the neighbor there is no chain door lock. (00:50:15 - 00:51:45)
Continuity mistake: After John races Jane home and goes in through the back, he breaks a pane of glass square with his elbow to unlock the door. About 1 second later, the break in the glass is different and no sound is heard of more glass falling off to change the shape.
