Continuity mistake: John's staff sergeant military shoulder epaulet markings become upside down in the scene when he and Savannah are having dinner at her house when he comes to see her after his dad died. In a later shot shortly after, they are correct.
Continuity mistake: When Eduardo finds the letter on the mantlepiece about them apparently stealing the idea for Facebook and asks Mark if they did or not, he places a bottle on the mantlepiece just before he finds the letter. This bottle rotates slightly between shots without him touching it after placing it down. (00:49:15)
Continuity mistake: In the scene where Carrie is telling the girls about kissing Aidan, her necklace (a crescent moon) keeps switching sides. (01:48:45)
Continuity mistake: When Teddy's kids are lying dead on the grass, the position of the girl's arms keeps changing between shots.
Continuity mistake: After the loco connects to the back of the train, a couple of scenes show the engine with the air hoses connected, and some do not. These hoses can only be connected from ground level.
Continuity mistake: In the scene where Sophie is first walking out of the New Yorker building, her shirt is tucked in in the first shot, in the second it is untucked, and in the third it is tucked in again.
Continuity mistake: When the 3 guys are kicking a single guy with Kick-Ass defending him and a bunch of people behind watching the fight, the trashcan on the ground keeps changing positions between shots.
Continuity mistake: When the police car rolls out of the car wash, both passenger and driver's doors are open. When the shot changes to the deputy holding the rifle, the driver's door is closed. In the next shot both doors are open again.
Continuity mistake: When Ray Winstone takes his pill with whiskey while talking to Mel Gibson, he takes a swig of the drink and knocks the pill back, leaving some alcohol in the glass. When we cut to a wide shot his glass is completely empty.
Continuity mistake: When Hiccup first finds Toothless, there is a dramatic shot where the camera pans over Toothless, and his wing briefly obscures his eye, which is open after the wing passes. But look at the tip of the wing. During the shot there is a stretch of rope wrapped around it. In the next shot, the rope is much higher up the wing and not wrapped around it anymore. (00:13:15)
Continuity mistake: On the inspector's boat Frank's wrists are handcuffed together with a railing between his arms to secure him in place. There is a very short chain between the cuffs, 4 to 5 inches at most. When he's pulled free by a rope from Elise's boat he starts 'climbing' the rope hand over hand. In one shot his hands are over a foot apart, he's obviously not wearing the handcuffs. When he gets onto Elise's boat his hands are cuffed once again, she shows him how to pick the locks to get the cuffs off.
Continuity mistake: When the karate kid first goes to Mr Han's house to train, he drops his jacket by the doorway. Later on as they are talking, you can see his jacket move to different spots on the ground between shots.
Continuity mistake: When Elizabeth meets Lionel for the first time, her face netting disappears and reappears between shots.
Continuity mistake: In the final dance Julien is wearing the samurai jacket, but when the camera changes angles and then focuses back he isn't wearing the jacket. This happens at least three times.
Continuity mistake: When Will has come to apologize and talk to Ronnie after she has left the volleyball game practice, Ronnie's father opens the door to a sweaty suitor. The door is closed and when it is reopened just a brief moment later, Will is no longer sweaty.
Continuity mistake: When Travis is attacked by Barris at the end of the experiment, he "catches" the knife and his hand is seriously injured, becoming covered in blood. However, when the red light begins to go off and Travis raises his hands to his head, both of them are clean and uninjured. (01:25:25 - 01:26:45)
Continuity mistake: After Jake signs the contract, the real estate seller lifts up her glasses. A frame later they're back down by the tip of her nose.
Continuity mistake: When Bennett gives David Stutler the red handkerchief David has no ring. When David opens the handkerchief he is wearing the dragon ring in the shot and then it disappears in the next shot. This occurs after Horvath has taken the ring from David in the previous scene.
Continuity mistake: In the first shot of the dead man hanging form the tree, his head appears to be about 12" from the tree limb. After Mattie climbs up to cut him down, his head is several feet from the tree limb.
Continuity mistake: When Aron Ralston falls off the bike he is thrown few yards away of his bike into a bush. However, when he is taking the photo the bike is under his head.