Revealing mistake: When Alex uses his time machine for the last time to destroy the Morlocks, watch the closeup of his machine when it's activated. In the lower left hand side of the machine you'll see Alex's laboratory in the background. This is confirmed by director Simon Wells himself in the DVD commentary.
Revealing mistake: When Charlie is writing her letter we can see it through a hidden camera in the pen she is using. By watching the angle on how the camera would be attached to the pen we know that she would have seen the camera. Also her hand would be blocking the camera view, so we shouldn't be able to see anything at all. (00:30:30)
Revealing mistake: When Barry is arguing on the phone with the Healthy Choices employee, the map on the wall behind him is creased in the Texas/Arkansas area before he punches it there. This could perhaps be the result of a previous take or some sort of indication of where the soft spot in the wall is so that Adam Sandler doesn't really break his hand. (01:00:25)
Revealing mistake: When the two main characters explode and then implode near the end, you can see that some of the debris being sucked in are passing "through" various other objects, revealing they are computer generated.
Revealing mistake: When the stabbed photographer is left sitting on the toilet the blood stains on his pants are virtually colorless. (00:32:35)
Revealing mistake: When Uncle Mike and Johnny go upstairs at the party to hustle Phil and company, Phil shoots the eight ball towards the corner pocket, and the sound effect indicates he made the shot. Phil says, "That's how we do it," but right as he says this, the eight ball is seen slowly rolling back into the shot, revealing he actually missed the shot.
Revealing mistake: When Tommy and her boys are roughing up Randolph in Angie's apartment, Tommy throws Randolph across the room into the piano. The vase sitting on top of the piano falls before Randolph ever touches the piano. Seen better in slow-mo. (00:57:20)
Revealing mistake: About 30min into the movie, there is a scene at an airport with a 4-engined 707 freighter. As the characters walk behind the jet, you can see that the left-hand inboard engine pod has no engine on it, unlike the outboard pod. The aircraft is obviously being dismantled despite the appearance of having just landed.
Revealing mistake: If you look at the instrument gauges right before the foil "bird" hits the windshield, you can see that the car isn't actually moving on its own because the speedometer is at zero. All of the warning lights are on also, meaning the car most likely isn't started at all and the key is just turned forward. (00:32:50)
Revealing mistake: When Stu is tempting the sniper to see if he will really shoot, the sniper shoots the phone booth, shattering the window, and supposedly hitting or grazing Stu's right ear. When Stu lifts his head, you can see his bloody ear. A few shots later, Stu's head is turned so you can clearly see his fresh wound. If you look closely, you can see Stu's real ear folded back beneath the fake latex one. This happens several more times in the next few minutes of the movie. (00:31:40)
Revealing mistake: When Gil is looking at the "Blip Abuse Continues" article, you can see the same paragraph repeated many times. (00:55:15)
Revealing mistake: When John goes to close Gordon's eyes, as he lowers his hand, you can see him close his eyes on his own.
Revealing mistake: In the scene where UB breaks into Feather office you can see a mark on the door where he is supposed to kick in order to break it.
Revealing mistake: When Simone is performing in concert, the auditorium is supposed to be packed full. But when the camera flies over the audience, in the background you can see empty space because only about 100 extras were recruited for the audience. (01:04:00)
Revealing mistake: It's nice to see that Alex (the helicopter pilot), is able to keep herself in such nice and kempt condition. Look at her... clean, washed and combed hair, makeup, and she's actually got lipstick on in one of the scenes.
Revealing mistake: The spy contact lenses that Owen Wilson and Eddie Murphy use were originally supposed to be for Carlos, but if you notice, the lens that Owen Wilson uses is blue to match his eye colour. Carlos has brown eyes.
Revealing mistake: When Kevin Bacon is talking to Courtney Love on their cell phone and he hangs up on her, a dial tone can be heard on Courtney Love's phone.
Revealing mistake: When you watch the accident scene frame by frame you see that Laroche's mother and uncle are replaced by dummies. You can see the joints in his mother's hands and a large spring that holds his uncle's head in place. (00:41:50)
Revealing mistake: When the people come to take the girls away, the mothers and girls run, with the camera in front of them. You can see the wheel tracks in the dirt from where it is being towed back.
Revealing mistake: When the boy runs from the jumping spider he crosses the road, which makes the eighteen wheeler lose control and it jacknifes. You can clearly see a set of tyres are moving with the right direction of the truck, and there are a set of tyres sliding. (00:40:55)