Continuity mistake: In the scene where Michael (Jeremy Piven) kills his brother Adam in the parking lot, you can see that when he pulls out of the parking space, he turns his vehicle around. The camera cuts from an outside view (where Adam's minivan is) to inside Mike's car. If you watch, Mike turns his steering wheel to the left but his car turns to the right when the camera switches back.
Continuity mistake: In the scene where Christian Slater is about to show the house to the perspective buyers, the man has dark colored sunglasses on, then when it pans back to him, his glasses are clear, and finally when the camera returns again to the couple he has his dark colored glasses on again.
Continuity mistake: When Cameron Diaz runs out on to the street at the end of the movie she is holding a toilet scrubber and a rag. She then falls down on the road and lies on her back screaming while the camera above her is rising. The view changes and the camera is higher (obviously on a helicopter now) but during this camera switch the toilet brush has gone from one hand to another.