Other mistake: When Fats makes the 7 ball after Eddie's safe play, you see the cue ball flying into the pocket before the camera changes shots.
The Hustler (1961)
1 other mistake - chronological order
Directed by: Robert Rossen
Starring: Paul Newman, George C. Scott, Piper Laurie, Jackie Gleason
Factual error: In the first match between Fast Eddie and Minnesota Fats towards the beginning of the film, Eddie, right after declaring he would start to win after losing thus far, shoots the one ball into the side pocket by shooting the cue into a striped ball. Sharp eyes will notice that he actually hits THROUGH the cue and strikes the stripe into the one with his stick. While a nice trick, this is an incredibly illegal shot and would never have been allowed.
Fast Eddie: I'm shooting pool, Fats. When I miss, you can shoot.
Trivia: In 1973, Paul Newman played Henry Gondorff in "The Sting." Jackie Gleason later played the same role in the film's sequel, "The Sting II."