Audio problem: Edouard wakes up Marianne after he returns to the art studio after walking out. The two walk over to a bench, then Marianne disrobes and sits down on the bench, so she can pose for him. Whilst this is happening, no further sounds can be heard in the background. Marianne then sees Liz sitting on the staircase watching her and out of nowhere, sounds coming from outside can be heard. The door to the studio would have been open the entire time as no-one is shown opening it, so the sounds coming from outside should have been heard the entire time. (02:14:42 - 02:16:14)
Other mistake: The sword champion is murdered in a dark room. Cut to Tarek Richards by his corpse. The room is still shrouded in darkness, which makes for a cool transition. However, when the camera pans out and someone (with an audible click) turns on the lights, you realise that the room is full of cops which up to that moment have been working in a dark room for no reason - and they have been doing things that require reading and writing, like collecting witness statements.
Continuity mistake: In the first meeting with the man with the hat, Ice puts one foot on the portable cooler, but the position of the foot on the floor changes when there's a cut. Even more obvious, when she steps in front of him, the tip of her red stilettos touch his feet, but at the cut their tips are distant, and she moves in with her right foot first, as opposed as before. (00:09:15)
Continuity mistake: When Jason and The Count duel, the cut on Jason's cheek is already there before The Count cuts him there. By that point, Jason was only cut on the shoulder.
Continuity mistake: David goes downstairs and finds out about his surprise birthday party. The tape recorder and the other objects on the table change position between shots around the ugliest cake ever. (00:05:25)
Other mistake: Despite Lena's cab driver and his wife both being Armenian, the wife's speaking Spanish.
Continuity mistake: It wasn't snowing in the front of the house (e.g, when Ethan, Hallie, and Stephanie were going home; when the ambulance arrived; when anyone came in the front door), but it was snowing heavily in the rear of the house during scenes showing the Christmas tree. (01:18:24 - 01:20:42)
Character mistake: Cynthia Kellogg comes forward to voluntarily give information about the James Urbanski case. Detective Nealy tells Kellogg, "As a matter of procedure, I have to inform you of your rights." Kellogg says she didn't do anything so doesn't need a lawyer. Nealy replies, "This is your right" and proceeds to inform her of her Miranda Rights. Miranda warnings are applicable to suspects/defendants who are in police custody (under arrest) and about to be interrogated, not voluntary witnesses. (00:03:02 - 00:03:57)
Audio problem: Al (Joe Mantegna) gets knocked down by a mighty punch from his wife Carla (Linda Fiorentino), who, after lying some more, grabs the two daughters to go to her mum's. One of the daughters flashes a smile and supposedly says, "Hi Daddy!", but the line is dubbed in. (00:15:00)