Factual error: When Swagger is fleeing from the police in the car wash after being shot, the radio says that he is at a car wash at 9th and Girard. There is no such intersection. On Girard Ave, 9th street picks up south and north of that street.
Other mistake: Based on the location of the barber's chair with the picture window in Todd's barber shop and the layout of the exterior of the building, there is no possible way that the chute behind the chair would be able to dump the bodies directly into the basement without going through the center of Ms. Lovett's shop.
Plot hole: Since they took down the telephone network, it would have been impossible for Justin Long to even be speaking to the emergency response woman for the car, much less send a signal to start the car up.
Suggested correction: Is it possible this is a satellite phone call akin to Onstar?
No, the BMW system requires a cell signal to work, which was taken down earlier in the movie.
Continuity mistake: When Miss Gruwell and the students are discussing junior year for the first time, she has her back turned and she is writing on the board. When she writes, "First Person Na", she turns around before finishing the last word, but in the next shot, "First Person Narrative" is written on the board.
Factual error: In the final standoff, Smith shoots Hertz by holding cartridges between his fingers in the fire. This is not remotely believable. The casings, weighing much less than the bullets, would have been blasted off while the bullets themselves would have gone nowhere. (01:15:15)
Continuity mistake: Nick's character is eating an ice cream in the police car and eats the whole thing. When the shot changes to Simon's side, he's still got about half of it left.
Continuity mistake: After they almost get run over by the man on the motorcycle, Jack receives a phone call. He answers with his left hand on his left ear, then it cuts and it's in his right hand and his right ear. It switches back in the next cut.
Factual error: If you pay attention to the backgrounds of the scene where Frank is in the airport and when Frank is being arrested as he walks from the church, you can see two cars pass by which weren't produced until at least 2000.
Continuity mistake: When Nancy defuses the bomb, leaps into the air and falls down, her head is rested on her arm when she is lying on the floor (in the first scene). In the next scene, her hands are both together and her head is on the ground. (00:50:50)
Visible crew/equipment: When stuntman Mike and the girls cars come back together after being separated by a pond, the shadow of a car-mounted camera crane is visible in the left bottom corner. (01:44:00)
Visible crew/equipment: Several times in the movie you can see a stunt double for Donnie Wahlberg, like when he tries to hang himself. Art runs over and there is a wide shot focusing on both of them. No slo-mo required, but you can see it's a stunt double.
Other mistake: Eddie comes to see Tom at the bathroom clean-up job and convinces Tom to confide in him. Eddie tells Tom that he'll, "See what Wallace knows". There is no character named "Wallace" - he was supposed to say "Vargas", the investigator on the case. The subtitles correctly reference Vargas.
Continuity mistake: In the scene where Dakota is having sex with Aubrey's boyfriend, it specifically shows that her bra is off. Once they finish, and she is getting off of him, she is covering her chest with the sheet. When she does this, her side isn't covered and you can that she is now wearing a black bra.
Continuity mistake: In the railway station where 47 is being followed by the FSB, Interpol and the older agent, you see the older agent running down the ramp to platform 9 after 47. His jacket is flying up in the back, and there is no weapon visible. When he stops running, he reaches behind him into the waistband and produces a handgun with a silencer.
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.
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: 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: 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)