Continuity mistake: First day in class, when Hoager "beeps" at Jesse, Mrs. Myers writes two words. The word "verb" is over the word "subject" on the board, in the close-up. After she turns around, in the following shots, the word "predicate" appears, disappears, then reappears and "subject" is written over "verb" now. Additionally, during this scene, all the other writing on the blackboard changes between shots as well. (00:06:15)
Other mistake: When Jennifer and Gary are scratching the messages to each other on the painted glass, the glass is painted black on both sides so they wouldn't be able to see each others scratchings as the paint on their side would cover the marks the other was making.
Factual error: Firearm issues abound throughout the film. The British detectives (who all seem to be armed, rather than a low proportion of AFO (Authorised Firearms Officers) as in real life) are shown carrying Beretta pistols, even though the Metropolitan Police issue the Glock 17. The SFO (Specialist Firearms Operations) officers are shown carrying MP5 submachineguns, which is accurate, but fitted with cheap toy-shop lasers. Weapons handling is poor throughout, with chickenwing syndrome particularly prevalent. Weapons carriage also appears geared to look "cool" rather than realistic; shoulder holsters - which practically everyone wears in this film - are rarely used for concealed carry in reality.
Continuity mistake: Near the end, when Lucy tries to get into the building, she is blocked by police officers holding clubs straight ahead in front of them. The scene cuts to a roof shot, then back again, and Lucy tries again, but the clubs are missing, the cops just have their hands out in front of them.
Continuity mistake: The "Power Play" scene when Eric and Hanssen are in the car after a cancelled meeting (13). With Eric's line, "There's construction on E Street," the Kennedy Center appears behind his head, but in the next shot of him ("Sir, I'm SSG.,") the Kennedy Center shows up again, this time farther ahead of the car. (01:05:55)
Factual error: When Bob Ford opens the box under the bed, on top is an issue of "The Jesse James Stories" weekly, which was published from 1901-1903 - fully twenty years after the events of this film. (00:36:10)
Factual error: In the scene when Kale uses the lamp, taking off its lamp-shade, to see what's inside the hole, he points it in there. The lamp, actually, shouldn't illuminate the wall in one point creating a circle like a flashlight but wholly lighten the larger area. (01:30:00)
Continuity mistake: While Jon is fixing his contracture with the weight on the door, the position of Wendy's toast on the plate keeps changing depending on the angle.
Continuity mistake: During the complete car-bomb chase sequence towards the end of the film, Michael Clayton's car is shown in one shot without its lights on. All the surrounding shots in the scene have both cars with their lights on. This is also a slightly revealing error because it shows that they actually filmed these sequences during the day using neutral density filters. (01:41:15)
Visible crew/equipment: In the scene towards the end of the movie when they are at the dinner table, Dory is telling Kelly about the time his father shot a squirrel and cried. If you look closely at the lower right hand window towards the back, you see a face appear in the window. It looks almost ghostly.
Visible crew/equipment: During the scene where Harrison raises his fist to Rowena, there is a brief moment when you can see what looks like a shadow of a boom mike and crew member behind Rowena's head on the ground behind her. (01:16:35)
Continuity mistake: As Mike scrolls through the microfilm, we see his view as the pages scroll from right to left. The shot then reverses to show his face through the scrolling film, but while the film is now properly reversed, it's still moving right to left in our view. But this reversed angle should show it moving left to right. (00:12:05)
Continuity mistake: The whole time Dan is in the bookstore and outside talking to Marie, he is wearing a blue undershirt. However on his way home from the bookstore, he runs a stop sign. When the cop comes up behind him you can see that his undershirt is now grey. When he gets home and walks through the door, his shirt has gone back to blue. So Dan's shirt changes a few times when everything is supposed to be in the same sequence of time and events.
Continuity mistake: In the scene outside the hospital, after Nick Poole has been shot, Remy Bressant picks up the bottle of liquor, which was capped by Patrick Kenzie and drinks straight from the bottle. The bottle has mysteriously uncapped itself.
Continuity mistake: When Jean-Do is shaving his father, there is suddenly a lot more shaving cream under his nose where he had already been shaved. Also, because the camera is so close, you can tell that he had no stubble anywhere to begin with. (00:55:30)
Factual error: There is a scene near the beginning of the movie when the mist has just begun. A firetruck roars by, and has Caddo Parish Fire Dept. on the side. This movie is set in Maine. Louisiana is the only state with parishes. All others, including Maine, have counties. (00:10:50)
Continuity mistake: In the scene where the mother, Denise, is finally beginning to believe their house may be haunted, and is questioning Ben as to whether or not he can see them, Ben points out the window. When Ben points, you can see that the curtain is over the window. When Denise looks back, the curtain is wide open so she can see the barn. When she looks back to Ben, the curtain is again closed.
Continuity mistake: After Evans was shot near the end of the movie, Ben Wade jumped out of the train to look at him. If you look over Wade's shoulder, you will see that Nez (the Apache) had already arrived at his spot, and Campos (the Mexican sharpshooter) threw Wade's gun belt to Charlie Prince. After the movie cut a couple of times, Nez was shown walking up, throwing Wade's gun belt to Campos, who then threw it to Charlie Prince.
Continuity mistake: The next morning after they have been attacked, the car windscreen that was smashed is now untouched.
Continuity mistake: When Amada and Bobby are on the bed kissing and Amada gives Bobby a gift, he pulls the gold necklace out of the box and says it's beautiful, then begins kissing her without putting it on, but in the next shot, the necklace is around his neck.