During the roulette scene, when 17 Black is called, from Jim's point of view he has 6 stacks of white chips, then the next view shows that he has only 1 stack of white chips when his bet is paid off.
In all the Casino scenes, the same names are paged over and over.
When Susan and Louise are fleeing in the Camaro the 2 closeup shots of the speedometer show a Mopar instrument cluster and steering wheel.
In the elevator Jim tells Louise to go to the basement, get in her car and go home. Only problem is they came to Las Vegas together in his car.
When Jim and Susan are driving from Las Vegas to Reno, there's a scene where the sun is directly in their eyes, even with the sun visors down. Since the trip is mainly North by North-West there is no way this could have occurred. There are 2 stretches where you are driving due west and the sun will be in your face if you are driving either stretch near sunset.