After Norman enters Kelli's room, the phone, candle and lamp on the desk move between shots.
As the dinner party is starting, it is near dark, probably a half hour from sunset. During the party a platter of food is sent flying out the window and the sky is completely dark. Later, when Norman and his friend leave the party, the sky is near dark, about a half hour from sunset.
When a porn actress makes love to the wind, and then Norman, she is undressed. As the scene ends she is suddenly dressed.
Reflected in the glass of the picture when the models are in Norman's office.
During a fight between two invisible men, a crew member can be seen shaking a shelf that the two men are supposed to have bumped into.