Early in the movie when Jim is at the blackjack table and wins an $80,000 bet with a natural 21, rather than being paid the correct amount which should have been $120,000, he is paid incorrectly as he receives 16 of the blue/white chips adding up to $160,000.
When Jim throws the TV on the floor, from the tub, the TV lands upside down, a couple of feet from the stool he's using as a TV stand. Subsequent shots of the TV show it face up, and right next to the stool.
At 01:11:00 Jim talks to Amy and his face looks better than few minutes later when he walks out of the campus and his face looks more seriously wounded.
When Jim is watching his mother's tennis game in the referee's chair, we see alternating shots of him from the front and the back. In the frontal shots he's wearing black shoes, but in the shots from behind (probably a different actor) his shoes are brown.
When Jim gambles for the very first time he takes a drink from a waitress. When he sets the glass down it is half full. Before his first bet at blackjack, the glass is empty. After losing everything, the glass is back to half full and he sips from it and crunches its ice.
At around 30 mins) When Jim Bennett is waiting for Big Ernie to pick him up, the crew is reflected in the side of a large black SUV which drives through the frame from left to right.
Neville instructs Jim to make sure Lamar doesn't beat Michigan by more than 7 points. During the game, the announcers refer to the opponent as cross town rivals. This is impossible as the film is set in California.
Lamar refers to Jim's car as a 'BMW M1'. Jim actually drives a 'BMW 1M'. The BMW M1 hasn't been in production since the 1980s.