Continuity mistake: When Dexter is at the bar after the faculty party, he's not wearing glasses. After he speaks to Sydney and asks her to have a drink with him, he's suddenly wearing glasses.
Continuity mistake: When Dexter confronts Mrs. Fitzwaring, she points a gun at him. That gun is a Beretta Model 70. However, later on in the confrontation, the gun she is pointing at him is now a Heckler and Koch P7M13.
Factual error: Radium Chloride (stated by the doctor to be the ingested poison) does have a slightly luminous glow to it, but absolutely doesn't have the intense shining bright green luminous glow that is shown at the end of the film in Professor Cornell's mug.
Continuity mistake: When Mrs. Fitzwaring shoots herself, she falls face-first onto the pool table, with the front of her left shoulder laying against the table near the narrow side. When Quaid looks back, she's on her back, and now the back of her left shoulder is on the table near the narrow end. Her body has flipped 180 degrees, meaning her feet had to flip over from one long edge to the other long edge. Very difficult for a dead person to do. (01:21:35)
Continuity mistake: When the car plunges into the tar pit, the windshield of the car alternates between being covered with tar (starting with Bernard sliding into the tar), to being uncovered (very next scene shows Cookie visible through the window, as well as the gunshot crack) This continues throughout the whole minute of the scene until the car is submerged. (01:09:30 - 01:10:20)
Revealing mistake: When Bernard throws his gun to the ground, the ground "wiggles". (01:09:15)
