Plot hole: In the scene where Ashley Judd runs away from her attacker and falls into her aquarium he has moved to the bottom of the stairs - there is no way he would have been able to move that full fish tank. It looked to be about a 30 gallon tank - it would weigh about 400 pounds with the stand and even if he slid it with some superhuman strength, glass tanks are notorious for shattering when you move them full. Plus it would've made enough noise to wake the dead - no way she wouldn't have heard it.
Continuity mistake: Ashley Judd has just handcuffed the bad guy to the stove, Morgan Freeman walks in and has the little talk with the bad guy why not to light the lighter and blow up the room. Just when Morgan Freeman shoots the bad guy in the head, the bad guy flies back with BOTH arms visibly flying backwards. In the next shot with the bad guy dead, his hand is once again handcuffed to the stove. (01:50:30)
Continuity mistake: Cross enters the interrogation room, with Dr. Sachs detained. He's carrying a cup of coffee and a file. He puts the coffee on the table, and in the next shot you can see already on the table the file that he never put down and is in fact still in his possession in the shot that follows. (01:21:05)
Other mistake: In the Italian dub, Dr. McTiernan talks to the two Chinese women with both of them speaking the language, making the dialogue quite paradoxical (since the point of the scene is that the older woman speaks only Chinese and the other has to act as translator). Not just that, but she introduces herself as Dr. "McTiernenson", for the one and only time in the movie. (00:21:10)
Continuity mistake: Cross is tired of waiting and pushes through the doors marked Main Offices. He advances through the open space; a policeman on the left of the frame is passing a file to a colleague sitting at her desk. Close-up of Morgan Freeman holding his badge, and the same policeman is repeating the gesture, arriving and handing over the file. (00:12:25)
Continuity mistake: Once Cross comes back home from the intro, he finds relatives there. Next to the mother there's another person (Cross' daughter, Janelle). She conveniently disappears between shots though, so Cross can sit next to May. She would have had to quickly backflip over the couch or slide on the floor to exit stage off-camera. (00:08:40)
Revealing mistake: In the locker of the Gentleman Caller there are multiple newspaper clippings. When Cross looks at the one talking about his niece, it just does not talk about his niece. The clipping is on camera long enough to be able to read without freeze frame, and it's talking about things like police brutality and apartheid (actual word used), entirely unrelated to the fake headline and picture caption. (01:18:00)