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.
Continuity mistake: When Newman first encounters Laurie at the diner in the bus station, in a wide shot we see all the empty tables behind her. He sits down and their conversation is shot in medium close-ups. In all of Laurie's shots, a man is now visible three or four tables behind her, flipping through a newspaper. When the conversation ends, we go to a wide shot, and, the guy has vanished. About ten minutes later, next day in the time line (I think), another scene in the same diner. Newman is already seated as Laurie walks in. She walks past empty tables to Newman. A few shots later, suddenly, in the background, the guy is back at his table with his newspaper! As they walk out the guy is gone again. It's the same guy at the same table appearing/disappearing in two scenes.