Factual error: When Mel Gibson is leaving NYC by car they come out of the Lincoln Tunnel onto route 4, that is impossible. The only way out of the Lincoln Tunnel is onto route 3. Then when they are driving through New Jersey on route 4, Mel Gibson says "There is the exit for 208." While you can get to 208 from route 4, they were driving on route 4 east, heading back towards NYC, not route 4 west which is the way onto route 208 they showed in the movie.
Other mistake: During a chase, Gibson makes a left turn at an intersection causing two girls to suddenly lunge backwards to avoid getting hit. The girl with the long black hair turns to her friend and smiles. This was most likely because she just successfully played a part in a big movie, but I don't think she'd be smiling at that moment. Most of the people in that shot don't react normally but are more explainable given the New York setting.
Continuity mistake: Near the end of the film, Mel and Jimmy Shaker go to the bank to get the money. When we see them going into the bank there is a blue car parked in front of the bank and it is covered in dust and is dirty. When they exit the bank the car is all clean and shiny.
Continuity mistake: Near the end of the movie, the woman kidnapper's tattoo has apparently slipped down about four inches after she's fallen down some steps, then it has sprung back where it was to start with.
Continuity mistake: When the first kidnapper gets shot in the rock quarry, his mouth is full of blood. Yet in the next shot his mouth is clean. (00:50:17)
Continuity mistake: Towards the end of the film, Gary Sinise is watching Rene Russo and Mel Gibson playing ball with their son. He is standing on a balcony. If you look in the background there are two people, a woman in a brown coat and a man in a grey coat. There are four different shots of Gary Sinise watching. The first shot has the people way back, the next shot they are walking off the scene, but the third shot has them back behind Gary Sinise again.
Continuity mistake: Renee Russo's hair goes from curly to straight towards the end of the movie.
Deliberate mistake: When the media truck follows Mel, he comes to a traffic light and stops. When he throws away the van's keys, he speeds off from the intersection. Why are the cars at his left not driving? They look like they have parked there and with no drivers present in the car. Weird for a very busy road.
Factual error: Police officers, FBI agents, any law enforcement employees are not allowed to collect on rewards. It is their job to return kidnap victims, catch criminals, etc.
Continuity mistake: Toward the end of the movie there are TV scenes of people on the street being interviewed. In the background all the cars are covered with heavy snow. When the scene switches back (not being shown on TV) there is no snow anywhere.
Continuity mistake: In the middle of the movie when Mel Gibson is in the interview room in the jail with the guy who he paid off to stop the machinist strike, the guy jumps at Mel and punches him. Mel gets up and he has a bloody mouth. A few seconds later after the guy is led out of the room Mel no longer has blood on his mouth.
Factual error: When the FBI agents are in the apartment they notice a flash from some photographers outside the window and they rush to close the drapes. A flash is only good for about 20-30 ft. and any half decent paparazzi would be using a fast film and no flash so he wouldn't be noticed.
Plot hole: When they rescue the boy he is with Gary Sinese. Surely the boy could hear his voice and tip off authorities he was one of the bad guys? Yet later in the movie when Sinese comes by the home for his reward, he hears Sinese's voice and recognizes it.
Continuity mistake: Towards the end of the movie when Tom and Jim are on their way to the bank Tom has gloves on when driving. Through most of the shot people are dressed for cold weather. However as they go by the side streets the trees are green with leaves, indicating late spring in NYC. When they arrive at the bank the trees have no leaves, indicating pre spring or winter conditions.
Continuity mistake: Earlier in the movie, we can see in the elevator that 16 is the highest number floor before the Penthouse (PH). Since they live in a two-story Penthouse, that would mean they are occupying the 17th and 18th (top two) floors of the building. But later in the movie when Mel Gibson hears the shot on the phone and thinks they have just killed his son, he runs out onto his balcony and looks down at the street. He is only about 4 or 5 stories up at this point.