Visible crew/equipment: When Sam, Carla and Diane are in Sam's office and begin laughing Coach walks in, laughs for a few seconds, and leaves. Right after that the obvious shadow of a piece of equipment (probably a camera) passes across the floor in front of Diane.
Revealing mistake: The photographs and news items relating to the Boston Barmaid Contest have been clumsily pasted onto a real newspaper. The paper upon which they were printed is cleaner and whiter than the off-white newsprint and the photographs have much greater contrast.
Continuity mistake: When Sam tells everyone it's closing time, he asks Harry how he got into the bar whilst he is playing snooker. He replies and then places a white snooker ball two inches behind a blue ball. There is also a yellow ball about three inches to the right of the blue ball. In the next shot, the yellow ball has suddenly moved a foot away from the blue ball. The yellow ball returns to its original position three inches away from the blue ball in the next shot.