Factual error: When Dodge and Lexie are in the building running from the police, you see an exit sign. This movie is set in the 1920's, before exit signs were invented.
Continuity mistake: During the lunch scene, when Jake is drinking Gatorade, the amount of liquid continuously changes between shots.
Other mistake: When the setup for the first match is announced, the Ram is said to fight Tommy Rotten "for the strap", which is pro wrestling slang for a belt, meaning it was a title match. But after the match, which he won legitimately, The Ram is not announced as a new champion, nor is he ever referred to as such, and no belt is given to him after the match.
Continuity mistake: Right at the beginning, the kid's hand keeps swapping from being on the middle of the paper to on the upper part, between shots.
Continuity mistake: In the beginning of the film, when Pitka is using the voice-over machine, it is a black machine. In the bar scene however, the machine is a pale-ish orange color. The orange-ish machine is also used in the ending scene before the song.
Factual error: There are Velcro straps holding the pads on the blocking sled, and there is an end zone goal post with one base. Both of these items did not exist until the late 60s.
Factual error: The basketball rims used in the movie are of the modern basketball era with "breakaway" rims. Such a rim was not used until after 1979, when Darryl Dawkins broke his first backboard in a game against the Kansas City Kings in November 1979.
Deliberate mistake: In the final fight, two master Brazil Jujitsu fighters, one an instructor and the other a champion, execute rear naked chokes without the requisite body locks, using the legs to control the body. In the first case, Mike was able to escape the choke by flipping backwards, which a body lock prevents. In the second case, Mike was able to strangle Silva even though any trained fighter could prevent it by simply twisting their body. (01:30:00)