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: When Adam Banks is playing in one of the games, he scores a goal and his teammates on the bench stand up and cheer when he scores. Problem is, Adam Banks is on the bench too.
Continuity mistake: In the convenience store, Link weezes the juice and gets slurpee all over his shirt. He gets kicked out and leaves, but 2 seconds later he comes back in the door and says, "I'll be back". At that point he has nothing on his shirt at all and it's completely dry.
Continuity mistake: When Meryl Streep "blasts" Goldie Hawn with the shotgun and Goldie falls into the pool of water, she falls in backwards. However, when we see her get up, she is getting up from a face-down position. (01:05:25 - 01:07:10)
Revealing mistake: After Mary Robert jumps out of the car, you can see the stunt double falling for her.
Continuity mistake: In his cameo in this film, Tim Burton is holding something in his left hand that looks like a remote of some sort when we first see him in the background. Then the shot changes to Debbie and back to Tim, but this time he doesn't have it. Then the shot changes to Debbie again and then back to Tim, and he reaches to his far right and picks it up.
Other mistake: During the scene where Markus and Jackie are making love for the first time, as she is straddled on top of him, you can see that she that she is wearing knickers (panties).
Other mistake: Towards the end where they steal the chip, they are detected and about a million security guards are all running around, yet 30 seconds later, the only security guard is one man with a shotgun. What happened to their big army of security guards? (01:41:30 - 01:42:55)
Revealing mistake: In the part it shows Ash getting sucked into the time portal you can see the wire he is hanging from. (00:02:45)
Revealing mistake: There is an obvious stunt double for Grandpa during the fight scenes.
Continuity mistake: In the first scene in Woody Harrelson's flat, Rosie Perez is in bed. Her top falls down, all but showing her breast; but in the next shot, she has covered herself up, but without moving her arms.
Visible crew/equipment: After the Peaches are introduced at their first game, they run onto the field. If you watch the background carefully, Rosie O'Donnell clearly trips over a production wire. (00:35:50)
Visible crew/equipment: In the scene where Darryl Knable is being sucked toward the satellite dish, you can see a crew member's hands lift him up into the air. (00:33:25)
Revealing mistake: During the ghost of Christmas present, Kermit is walking with tiny Tim on his shoulder and you can tell Kermit is walking on a spinning drum. Right before the camera pans away you can see Kermit's feet slide like he stopped walking but the road kept spinning. (00:55:00)
Continuity mistake: When Buffy is out shopping for her dress and Pike is on his bike beside her, they stop to talk and have an argument. Buffy walks off and Pike turns his bike around to drive off, but as he does this, his bike suddenly moves a few feet away from the wall he was right next to in the previous shot. (01:01:05)
Continuity mistake: The scene filmed in 'Daves Bar-B-Q' is across the street from a bank that has an outdoor sign indicating time and temperature visible through the restaurant window behind Vinny. When the meal begins, the time is in the 12:00 o'clock hour. Seconds later when the clock is visible again the time is in the 4:00 o'clock hour. The judge only permitted a 60 minute recess. (01:34:20 - 01:36:00)
Continuity mistake: Toward the end of the movie when the Dragons are facing the Giants for the Pennant, Hammer is up to bat and get a hit. When you see him round first base, they show a picture of the dugout, where you will find him holding a large hammer. It's tough to be at bat and on the bench.
Factual error: During the movie, Doug watches video from the previous Olympic competition. The skaters are shown performing in a darkened arena lit by spotlights. Special lighting effects like this are not allowed in competition. All competitions take place in a brightly lit arena.
Factual error: The baby is expanded to approximately fifty times his height, width and girth but it's explicitly stated that he retains his orginal mass. This means he will have the same volume as one hundred and twenty five thousand babies of his original size, but will weigh the same as before he was enlarged! That child is going to weigh much less than the volume of air he displaces. He's going to float away.
Continuity mistake: When Wayne and Garth are on their way to the Alice Cooper concert they show the car from behind you can clearly see that Garth is driving and Wayne is in the passenger seat but when they cut back to the car from inside Wayne is driving and Garth is in the passenger seat. (00:56:50)