Factual error: At the start in 1989, when Mike is dancing with the cheerleaders and also just before he goes after Scarlet, in close-ups of the crowd cheering there is a man (with a white baseball cap) wearing a Paramore t-shirt. However, Paramore (a Grammy-nominated American pop rock band) formed in 2004. The style of t-shirt he is wearing is actually one of the officially licensed Paramore merchandise. (00:02:45)
Factual error: After James leaves the bar and is driving, you see a dealership in the background and you can see new trucks and a new model yellow mustang. The movie takes place in 1987, so the vehicles are about 20 years too new. (01:26:00)
Factual error: Many of the songs featured in the film, almost all of which are portrayed as being singles actually being played by the disc jockeys, came out after the 1966 setting of the film, including Procol Harum's "A Whiter Shade of Pale" (June 1967), Tommy James and the Shondells' "Crimson and Clover" (November 1968), The Who's "I Can See For Miles" (October 1967), Jimi Hendrix's "The Wind Cried Mary" (May 1967), the Turtles' "Elenore" (November 1968) and Herb Alpert's "This Guy's in Love with You" (April 1968) among several others.
Factual error: In the credits, Josh Peck is said to voice Rudy. He actually voiced Eddie.
Factual error: Prince Albert was not really wounded in the assassination attempt depicted near the end of the film. Eyewitness accounts differed as to whether he pushed Victoria down to protect her or simply dived for cover himself, but neither of the two bullets fired struck either of them.
Factual error: The alligator mentions wanting a Bananas Foster. This dessert was invented in 1951 but this movie takes place in 1926.
Factual error: When Henry travels back to when his mother is still alive and is riding the el train with her, when he gets off the train downtown there are color coded signs on the platform. Specifically, a brown and purple sign indicating that those color trains stop on that side of the platform. This scene took place sometime in the 1970s since his mother was still alive, but el trains were not color coded until 1993.
Factual error: When Ben goes to Anna's yoga class, we see the very end of the class. Everyone is seated upright, cross-legged. In real life, yoga classes always end in savasanah, a pose where you lie on your back and breathe to take in all that the body/mind just did. They just had the actors seated upright to show them making eyes at each other.
Factual error: When the Lincoln Continental Convertible was rolling backwards down the hill, Nick put his hands on the trunk to try to stop it. A car, especially one weighing 5,000 - 6,000 #, would easily knock over a person and possibly cause serious bodily injury (even death). Nick's attempt to stop the car by holding onto the driver's door handle would also be futile and potentially dangerous. (00:37:47)
Factual error: About 30 minutes from the end, the rodeo parking lot is shown, with the cars parked 3 deep (i.e., 3 cars parked nose-to-tail). Valet parking? At a Wyoming rodeo?