Other mistake: When the gang are watching the news report in their van, Heather Jasper-Howe shows the clip of Fred saying "I think Coolsville sucks" - problem is that there was not enough time for the crew to edit Fred's short interview and be able to transmit it that quick. (00:37:00)
Other mistake: When Exley talks to Vincennes about Rolo Tomassi, Guy Pearce's Australian accent accidentally slips when he says, "I just wanna solve this thing." (01:26:20)
Other mistake: When Daniel is playing Guitar Hero with his friends, after he and his friends leave the game to go outside, if you look closely at the TV, you can see that the game is still playing (notes are still being strummed) even though there is no one at the controls. (00:23:05)
Other mistake: Although the Lieutenant is actually sent to the police station in precinct 9, division 13, the sign over the door states it to be division 14.
Other mistake: When Walker and Michelle fall down the steps at Dede's apartment, Walker lights a match to show Michelle the matchbook. The light from the match flickers on their faces but if you watch closely you can see the match go out as soon as Walker strikes it. (00:54:45)
Other mistake: When Nancy finds the trapdoor from the attic, she goes down a ladder and gets onto the other floor. She walks a bit and goes down another ladder then looks up and Ned throws the flashlight straight down to her.
Other mistake: After speaking with Dave Bowman on her TV, Betty lays her head on the table and we see an obvious cut & paste as her form shifts slightly. (01:09:35)
Other mistake: Frank visits Walenski just before the tuning, but the clock in his house says it is 1 o'clock. (00:27:17)
Other mistake: When Taryn turns into a punk and walks down the alley way, you can clearly see Freddy's back along the bottom of the camera shot as if he is trying to pass the camera for the next shot. This happens as Taryn looks down the alley. However, if that was meant to happen, wouldn't she have seen Freddy, and not have been so scared when he approached her from behind?
Other mistake: Right at the very end, when all the prisoners are standing in the room, it starts to slowly zoom in on Alice in the middle, but watch the blonde girl on the left of Alice - she starts laughing for no reason at all as Alice smiles to herself. I don't think it had anything to do with the film either, because it didn't show any reason why she would just start laughing like that.
Other mistake: When Owen first meets Dodger, and asks if its that obvious he's a transfer, she tells him "It's a small school, word travels fast." During a flashback to this scene at the end of the movie she says "word spreads fast," instead.
Other mistake: Hayden Christensen's character is credited as Jake Hill Conley (seen in both the end credits and on IMDB) but when they explain who each boy is and why they were picked to take the girls to the dance, the voice-over calls him Joe Hill Conley.
Other mistake: In one shot, during the lynching, the noose comes undone from the character's neck while he is hanging.
Other mistake: At the beginning of the New York chase sequence where Bourne is walking down the street, you can see an Asian man smiling right into the camera for a second.
Other mistake: When Sarah is at the computer she creates a new directory and names it "JULIE". However when she opens the "JULIE" directory on the side it says "Julie" (not "JULIE") while the address path remains as it should be "C:\WINDOWS\Desktop\JULIE". (00:43:20)
Other mistake: In the scene where Jensen is attempting to decrypt the password on the hard drive with the algorithm, he uses the command "traceroute d-hea" which is commonly used to test network connectivity, not decrypt passwords.Then follows it with the command "dir" to reveal HTML code instead of directory structures.
Other mistake: The morning after the creatures give warning, the camera pans across the village. To the right, just left of the school, is the house where Lucius is put after he is stabbed. Notice the two smaller windows to the right of the door. Fast forward to the last scene, Noah's parents are sitting on the left and behind them you get to see the window frames are larger than the windows seen from outside. My guess is that the windows were bricked up so there would be better lighting for that scene.
Other mistake: Toward the beginning, when the characters wonder aloud what the rumbling noise is, someone suggests that it's the ventilation system, to which Rennes responds "No vents." However, in the passages between rooms there are panels with ventilation slits in them (which you can plainly see even as Rennes says the line), and it's pretty impossible that the characteristically level-headed and observant Rennes wouldn't have noticed that.
Other mistake: The same shot of two guys looking at a computer while sitting outside on the school campus is used in two different scenes. (00:02:15 - 00:11:35)
Other mistake: When we see the body of Liz Stride after her throat has been cut, the blood is bright pink. This may be due to the light shining on it, but it's still pink. (Surely by then, the blood would have turned brown after mixing with the oxygen?).