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.
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.
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. (00:39:20 - 00:40:15)
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).
Factual error: Jack exits the elevator on the 7th floor, going into his office - numbered 316. (01:26:25)
Continuity mistake: Jack unties the gag by hand, then is putting away his switchblade as if he had cut the gag. (01:38:30)
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).