Continuity mistake: When Nicholas and Christine are starting to leave her apartment after Nicholas smashes the smoke detector, Christine puts on her coat, then it cuts to the CRS van. When it cuts back to her, she only has the coat on her right arm.
Continuity mistake: In the scene at the restaurant, when the waitress runs into Michael Douglas and they both get wine all over each other, watch her shirt carefully. In one shot there are many wine stains all over. The next shot, there's not much. Then it goes back to having lots of wine stains.