Continuity mistake: After they almost get run over by the man on the motorcycle, Jack receives a phone call. He answers with his left hand on his left ear, then it cuts and it's in his right hand and his right ear. It switches back in the next cut.
Continuity mistake: When leaving the building, Jack Gramm's Porsche has rims with 18 spokes; when arriving, the car has different rims with only 5 spokes.
Revealing mistake: When Jack Gramm's Porsche explodes and make a flip in the air, the rear compartment where the engine is supposed to be is empty, and the rear axles and the tailpipes are common pipes.
Factual error: This movie takes place in Seattle. However, when Jack gets his car and drives out of his office you can see a Bell Canada building.
Continuity mistake: There is a lot of moving from one place to another during the last 10 minutes (supposed to be actual 10 minutes of the timeline), which seems pretty much impossible - from Jack's apartment to the girl's apartment, then to the office on campus, then to another building, up to floor 7, and they still have time to talk for a couple of minutes. Note that the glass doors to the elevators are locked, so he has to take the stairs, which are also behind a glass door that happens to be open. And how did he get through the police block on campus? There was a bomb threat just about an hour and half before - there is no way he would be allowed in there. Notice that the campus streets are empty so he can run without problems from his office to the other building.
Factual error: In the beginning when Dr. Gramm goes to his office, there is an orange "24 Hours" newsstand. "24 Hours/Heures" are Canadian newspapers published in major Canadian cities, but not in the U.S.
Factual error: In the first scene, when Pacino exits his apartment, you can see a Shoppers Drug Mart in the background. This is a Canadian pharmacy - there are no locations in Seattle. Also, during any scenes in the city, you can see that some scenes have traffic signals which have a yellow case (Canadian traffic lights) and some have black cases (American traffic lights).
Continuity mistake: Jack unties the gag by hand, then is putting away his switchblade as if he had cut the gag.
Continuity mistake: In the stairwell, Ms. Douglas wipes blood from her nose, but in the next shot, there is no visible trace of blood on her face. In the next scene at campus security, the blood is again on her face as it originally was.
Plot hole: This could be a "suspension of disbelief" issue, but at the climax of the movie when the murderer's accomplice gets shot, Jack has to grab the rope to save the dangling Dean. Objects (including people) fall at 32 feet/second, and speed up after that. That's roughly 10 yards/second, which is the speed of a world class sprinter. Jack was a speedy fellow to get to that rope, especially with street shoes, no starting blocks, and a slippery surface to boot (not to mention his age).
Continuity mistake: After Jack receives his first phone call whilst giving his lecture, he places his mobile phone screen down, then when it rings again it is facing up with the screen visible.