When Arlene is spitting out the vodka in the sink, it's daylight outside, even though it's supposed to be nighttime.
When Trevor is drawing his "Pay it forward" diagram on the black board, the diagram has clearly already been drawn once and erased.
When Trevor is eating breakfast in the kitchen with his friend, the contents of his breakfast bowl and glass change between shots.
The same man walks out of the casino twice when Eugene meets Arlene there.
At the beginning of the movie, the clock in Mr Simonet's room never moves. It reads 8:00 in every shot.
The point of triage in an ER is to identify and treat patients in need of immediate care. No nurse in his/her right mind would pass over a girl having an acute asthma attack for an obviously stable man with a gunshot wound, no matter what order they arrived in.
In the ending credits, special thanks are given to "O'Callaghas Middle School." This should actually refer to O'Callaghan Middle School, named after former governor Mike O'Callaghan.
When Chris Chandler is interviewing Trevor, the DVC Pro video camera his girlfriend is using, shown clearly from behind, obviously has neither a battery nor a AC power converter.
After Arlene slaps Trevor, she goes into the garage looking for stashed alcohol. On the right side of the shelves she searches, there are two boxes of powder laundry detergent stacked one upon the other. Although each would weigh a few to several pounds even if only half full, she brushes them off the shelf with just a flick of her hand, revealing the boxes to be empty.
When Chandler is talking to his girlfriend before he leaves to go to Vegas, audio is heard but her mouth isn't moving.
Just before Eugene reveals his childhood story to Arlene, Eugene steps out of his car. The camera man and the light from his camera is reflected in the window and door of the car.