Factual error: Cruise is breaking and if you watch the eight ball after the break it's following the 5 into a pocket at the end of the table closest to Tom. Now the 8 ball didn't necessarily go in because they focus on the one ball, but in the next frame shot, there's no way it could be at the opposite end of the table like they show.
Continuity mistake: At the very start of the tournament, when we see all the platters break at the same time (wide shot showing all tables), we see Eddie's table is second from the left and three tables up. Notice the referee one table behind Eddie. In the close shot after the break, we now see that the referee, who was standing still in the wide shot, is now a table further down.
Revealing mistake: When Paul Newman is playing in the tournament near the end after Tom Cruise humiliates him by dumping the game, Newman lines up to shoot the 2 ball. The point of view shot shows his detailed reflection on the ball's surface. If you look closely at the bottom right side of the ball, you can see that the "reflection" of his shirt exceeds the outside boundary of the ball.