Continuity mistake: When Magneto lands the Golden Gate Bridge on the island, as it hits land it is still very light. When the Brotherhood start to walk toward the island, it cuts to a wide shot of them still walking on the bridge, and it's suddenly dark.
Continuity mistake: At the end, during the fighting in the Cathedral, the last woman left is getting first cut by Steven Seagal at the right breast. A moment later, her cut is on her left side. The next moment it is on the right side again.
Continuity mistake: Nick goes out of his office and to Bristol's desk. Bristol starts standing up. Camera angle changes to Nick then back to Bristol. He starts standing up again. (00:40:40)
Continuity mistake: Hugh Jackman puts a tan vest on twice in the scene when we first meet his wife.
Continuity mistake: When Denzel Washington is taking off his clothes to be sent back in time. We see him take off his blue shirt. The shot then changes to look at the other guy and we see him take off his shirt again.
Continuity mistake: In the scene where Lois Lane is holding her son as Lex Luthor is revealing his plan to her the ring on her left hand switches back and forth between her middle and ring fingers. (01:25:05)
Continuity mistake: When the girls are told to stop reading their Goosebumps books, and go to bed, they put them down on the bedside table. In the next shot through the window, Jenna is seen putting her book down again.
Continuity mistake: In the scene on the roof after the power transfer, Hannah falls through the sky light and Matt yells down to her. You can tell the close-ups on Matt were re-shot because Matt's hair is longer and styled differently in between shots.
Continuity mistake: In the end, all the pictures in the cousin's book are normal, but earlier Leroy tore Xs in each.
Continuity mistake: When they are auditioning for the team, they stamp the fat kid's file "approved" under his photo parallel to the bottom edge. The camera cuts away and back to show the stamp at an angle with part of it on the photo itself. (00:13:40)
Continuity mistake: When we see the first instant messaging conversation between Stone, Izzy, and Tim, Tim's screen name is "Tim86". However, when Tim starts talking to Stone, it has changed to "Tim79."
Continuity mistake: After they ditch Burns in the woods, they plan to go through a small graveyard. As the captain starts briefing the squad we see him taking the cigar out of his mouth. When it cuts the cigar is back in his mouth. (00:21:40)
Continuity mistake: In the scene where they start filming the autopsy, Gary has his suit helmet on. When the character behind the glass causes the filming to stop, you can see Gary's helmet is off in the reflection in the glass, but when the camera cuts back to Gary his helmet is back on again.
Continuity mistake: After Hellboy defeats the semi-vampiric heads, the Professor is seen destroying a small statue on his scroll representing them. Despite being destroyed, this statue reappears later in the movie.
Continuity mistake: In the scene where Thor hits Hulk with his hammer, he swings it, but in the next shot it shows him with his arm extended as if he hit him with his fist. (01:01:45)
Continuity mistake: When Ernie lifts the bike, he picks it up by the top wheel. When he is shown carrying the bike a second later, he is holding it by the lower bar.
Continuity mistake: In the scene where Dean Cain's character and the girl are chained together with the shackles. Dean leaps through the window and crashes to the floor. The girl then jumps through the window and neither of them is wearing shackles. There was no cut, and no indication they had a key.
Continuity mistake: When the monster puts down Hanso after she tries to escape, you can see her footwear is completely dirty, but in the next shot where the monster's tail uncoils itself from her body, you can now see the pink and white of her footwear that you couldn't see before.
Continuity mistake: When Joey Lawrence and the rest of the androids catch up to the run-away prisoner after Lawrence lets them go, they tell Joey to walk towards him. Each back shot of Joey he has his right arm in front of his chest. Every front shot both arms are at his sides. This happens the whole scene.
Continuity mistake: When the guy who swears way too much is pointing a flamethrower at the two other characters in the garage, he's holding the flamethrower nozzle in his right hand. But when he goes to roll up his left sleeve to show them his arm, he uses his right hand, and it's a direct sequence cut (note the left hand is visible in the same shot and is not holding the flamethrower). After he rolls his sleeve up, he's holding the flamethrower nozzle in his right hand again.