Continuity mistake: In the first film, it is mentioned several times that Kevin is 8 years old. However, in this film it is stated that he is 10. When his parents are in the Miami airport security office, they say that he was left alone last Christmas. That would make him 9. Both films take place the same days, from about three days before Christmas until Christmas morning, so even if Kevin is born around Christmas time this is still a mistake.
Continuity mistake: The tiger bites the seat off the suitor's trousers, allowing the viewer to see his polka-heart boxers. When we see the tiger in the courtyard, he has a part of the same boxer shorts in his mouth. So if he bit off the seat of the trousers, shouldn't he have purple cloth in his mouth? (00:11:45)
Continuity mistake: In the scene where Gabriel Byrne is dancing around the fire with the travellers, he is wearing a large leather coat. After the police come and go, he's no longer wearing the coat. In the same scene, it shifts from night to day quite quickly, too quickly to be a sunrise.
Continuity mistake: At the beginning, there is a scene where Ben spills a carton of milk. He picks it up right away, but a split second later the scene changes, the milk is still lying down, and he puts it upright again. (00:06:25)
Continuity mistake: When Whistler is driving the van, he hits the two cars and knocks out the driver's side headlight, yet right after this and through the rest of the film, the headlight works properly. (01:51:25)
Continuity mistake: When Mr. McGuire is shot, he falls down, and Shannon's spoons spill out all over the ground. In an overhead shot, all the spoons are snatched up by bystanders, but then it cuts to a ground-level shot, and they're back on the ground, getting snatched up again.
Continuity mistake: During one scene, Mel Gibson is talking to the young boy through the treehouse door and holding the boy's jacket. The next scene, there is no jacket and then it magically reappears. (00:35:30)
Continuity mistake: When Nick and his dad walk to the kitchen to see what happened with the baby, Nick leaves the newspaper sideways on the table. He and his dad run back screaming and hide behind the couch. Angle changes and the newspaper is now placed perfectly straight.
Continuity mistake: When Duncan tries to explain his version of the raid of the Camerons' lodge to Cora part of his uniform is a read seat-belt-like piece of cloth. This wasn't there in the scene preceding imediately. (00:47:30)
Continuity mistake: When Bronx go to sleep intoxicated (the night the medicine man paints on her face) she is wearing a shirt and panties, but when she wakes up she is wearing a pair of jeans.
Continuity mistake: As Hampton's family leaves town for Happy World Land, the car's odometer approaches 100,000 miles and, at this point, Wade grabs a camcorder with his right hand and starts videotaping the event. But in the next shot however he's steering the car with both hands - and still operating the camcorder somehow. (00:05:50)
Continuity mistake: When Master Pan chases Li to a back area, a couple of guys stop to fight him to give Li a chance to get away. The one with short dreadlocks throws a jump spinning kick at him, and he Pan sends him flying into a ramp with his sword. Later, while Pan is fighting Eric Lee, there is a quick shot of that same guy sitting on the ramp very relaxed, then he vanishes entirely.
Continuity mistake: At the end of the fight in the gym, Mr. Horn comes in and stops it. Yet in the previous overhead shot, he is nowhere to be seen. The shots are meant to be directly connected - watch Cellini's hand. In the overhead shot, he starts brushing his hair back. In the close shot, he finishes the motion from the exact point he stopped in the overhead shot.
Continuity mistake: Peter Weller draws his automatic pistol and cocks it using the slide. He turns to the prisoner. The shot changes and as he walks behind the prisoner he cocks the gun again.