Character mistake: Whitney Houston's character, Rachel, is arriving at the Oscars and waves at the fans outside. A fan is holding a sign and it spells her name as "Rachael". When Rachel wins her award, her name on the TV is spelled "Rachel". (01:40:35)
Continuity mistake: At the Academy Awards scene, when Frank shoots Portman the second time, Portman receives an (entry or exit) wound on his temple. However, the way he was standing after being shot in the chest the bullet could only have hit him from the front. (01:53:10)
Suggested correction: The second shot hits the camera. The wound on the side of his head is debris from the camera.
Continuity mistake: The birthmark on Rachel's upper lip undergoes some make-up related changes throughout the movie. However, it shouldn't have disappeared completely between the moment she says good-bye to Frank on the airport and when she sits in the plane a few seconds later. (01:56:45)
Visible crew/equipment: Towards the end of the movie when Whitney Houston is in her hotel room with Kevin Costner you can see the mic in a reflection in the window of the suite.
Continuity mistake: When Frank's dad is cutting mushrooms while cooking dinner, he slices a mushroom in a closeup. In the next shot, the mushroom is whole again.
Continuity mistake: Right after Frank gets shot he shoots Portman and you see someone helping Frank get his jacket off as he's lying on the ground. The camera angle changes and you see his jacket back on and someone is starting to help him take it off again.
Other mistake: After Frank's first visit to Rachel's house he's in the car and in the last close-up shot of him when he's about to drive away, he puts the car into park.
Factual error: Outside the Oscars, the camera pans around to show the crowds and the security guards on the surrounding rooftops. One is holding a rifle which he should be, however there is another guard standing next to him overlooking the crowd holding a shotgun. This makes no sense at all, if he were to ever use that weapon from his position he would hit dozens of people.
Continuity mistake: When Frank pursues the killer at the lake house, through the snow-clad forest, his breath doesn't show. But he comes from a warm house directly out into a freezing night air.