Continuity mistake: When Kevin goes to the grocery, he buys Tide detergent. While walking home, the two bags break, but no Tide detergent falls out.
Factual error: In circling over Washington Dulles, a plane would fly over several airports that they could land at with perfect communication, including Richmond, Baltimore, Andrews AFB, etc. Also, there is no communication from the airport to the plane but the plane would be in range of no fewer than 15 transmitting stations that could have relayed messages.
Revealing mistake: When Carl is being dragged away by the demons, you can see the cable line that he's attached to. May be fixed on DVD.
Other mistake: In the slaughterhouse scene, after Harrigan has injured the Predator with his shotgun and Keyes reappears, the Predator throws its disc, and severs Keyes in half at the waist. We see his legs flop to the ground, and blood pour from above, but his upper half (torso, backpack and weaponry) mysteriously remain hovering out of sight. (01:21:50)
Revealing mistake: Near the middle of the movie Samantha Mathis is walking across the high school campus. The name of the high school in the movie is "Hubert Humphrey High School, " but behind her, above the library door, a sign says "Saugus High School Library". Shows better in 4.3 aspect. (00:31:45)
Factual error: Mel and Goldie board a ferry. A visible sign states 'Detroit-Racine Ferry'. Detroit is on the east side of the state of Michigan but Racine, Wisconsin is west of Michigan, across Lake Michigan. The only water route to get from Detroit to Racine would be to circumnavigate the entire state of Michigan.
Factual error: Though extremely modest on today's standards, the dress worn by Clara to the hoedown shows far too much cleavage for the time. No schoolteacher would ever wear a dress like that in the 1880s.
Revealing mistake: Doug has the hologram when inside the alien nuclear reactor, and a bunch of bad guys encircle the holographic image and fire at it at point blank with automatic weapons, and not one bad guy gets hit. If they encircled the 3D image, at least a few bad guys would have been hit by their own men. (01:37:00)
Plot hole: At the end of the film, we see Edward carving ice sculptures in his mansion. How did he get the ice up there? First of all, it takes place in a warm climate and I didn't see a freezer up there in the castle. He couldn't have gotten ice from town because firstly he had scissors for hands and couldn't have gripped the ice. And, even if by some miracle he could, he wouldn't be able to buy any from town because everyone in town but Kim was convinced that Edward was dead, she told everyone that they killed each other. And Kim didn't bring it to him because she told her granddaughter in the end that she never saw him again after that night. So where did he get that ice?
Continuity mistake: At the end of Rocky IV, Rocky's son Robert is around 6 or 7 years old. After Rocky comes back from Russia in Rocky V, his son is around 12. While there was a 5 year interval between Rocky IV and V, no time had elapsed from the two in movie time. So, therefore, his son should still be the same age given that Rocky has just recently fought Drago, "The Russian" considering his bruises, and they all returned home right after the fight.
Continuity mistake: At the start of the movie when the gun store is being robbed, one of them fires a portable rocket launcher at the police car, causing it to roll over and spin. As it comes to a stop just outside the store, it's visible that the driver's side window has been blown out, and the vehicle interior is visible, however when the same guy prepares to fire the bazooka to finish it off, the window has returned and is completely intact.
Revealing mistake: In the library scene when Richie sees Pennywise the clown, all the balloons filled with blood are popping on people who aren't supposed to be able to see them, but one lands on a lady and you can see her jump as the balloon pops.
Revealing mistake: When the scientists inject the mouse with poison, they put it in a jar. The, after they place it down you can see someone's hand swap the jar for one containing a dead mouse. You can even hear it. (01:17:58)
Continuity mistake: When Ford and Jazz are at the Colleen Sutton party, Jazz is asked to keep an eye on Colleen. Collen spots her and put a CD down her dress with the black end facing downwards. When Ford is taking the CD up from her dress the black end is now facing upwards. (00:43:25 - 00:45:00)
Revealing mistake: In the opening scene where the zombie kills Johnny. When they fall against the tombstone you can tell it is a dummy.
Revealing mistake: When the lawn mower the heroes send off as a diversion crashes you can see a wire pulling it. (01:01:30)