Factual error: In the scene straight after the opening credits we are taken to Baker Street where construction work is being done. This work is identified by a sign with a logo as being for the underground line. The logo type face was developed by a Mr. Edward Johnston for London Underground from 1913 but the distinctive typeface used in the film was not in place until 1919. This is obviously long after the 1891 setting of the film.
Factual error: When the bus slams into Brian's car at the start, Brian's car doesn't move an inch. Given the speed and weight of the bus, Brian's car should have been shunted a good distance. (00:01:45)
Factual error: As an attorney, I know that one doesn't become an attorney three days after passing the Bar Exam in NY, as Miss Lovenko claims at the end of the movie. She first would have to be approved before the Character Committee, submit Letters of Recommendation of Good Character, and her background would have to be checked. If approved, she would have to wait be sworn in by an Appellate Division Judge, which is about a 6 month process, not 3 days. (01:35:25)
Factual error: The Lincoln license plate reads NTGUILTY which is 8 characters. The maximum allowed on a California license plate is 7 characters.
Factual error: In the scene where Jack Black is kneeling over Shirley MacLaine's body in the garage, you can see the outline of his smart phone in his pocket.
Factual error: In the climax of the movie, Nicholas Cage uses a nail gun like a marksman, hitting with precision the bad guy that holds his wife tight. Besides this skill of his coming out of left field, a nail gun does needs a surface against the opening. It does not shoot nails in the air without pressure being applied, it's a Hollywood trope. (01:18:45)
Factual error: During the pre-credits sequence, when the Driver is attempting to escape the police, the sound of the engine accelerates with the rhythm of a manual transmission while the model on the screen has an automatic transmission.
Factual error: In the very last scene, Mikael and Erika get into a taxi and head off. This is on Bastugatan in Stockholm, and they are heading west. Bastugatan is a one-way road, and you can only go east. (Go to Bastugatan 14, Stockholm, Sverige and look west, the scene is very distinctive, as is the Do Not Enter sign.)
Factual error: Spoiler alert - When Henry's body is recovered under the 4th Street Bridge in Los Angeles, the 6th street bridge and the 7th street bridge (the one that he fell off) are each visible in the background. Meanwhile the water is visible moving towards the 7th street bridge which indicates that his corpse floated against the current. (00:22:20)
Factual error: Danny Greene has a bomb placed in Shondor Birns' car. As Birns is waiting to cross the sidewalk, the pedestrian walk-don't walk sign is a modern digital sign, that was not around in 1975.