Factual error: When the Titanic sinks all six dwarves and Kevin end up in the sea clutching a lifebelt. The water in which the Titanic sank was freezing - that is how most of the casualties died, by freezing, not drowning. In water like that you'd be lucky to stay conscious for more than a few minutes. Despite this none of them show the slightest effect of the cold. Maybe the dwarves have some 'magical' ability to withstand lethal cold, but Kevin doesn't even react to being plunged into freezing cold water. He'd be screaming in pain, but he doesn't even show the slightest sign of discomfort.
Revealing mistake: When Loomis shoots the marshal's window out, when he makes a u-turn you can see the tire marks on the road and dirt from previous takes.
Continuity mistake: When Scott gets his throat cut, blood pours out. Yet when Terri spins him around, there's no blood anywhere on him except a small amount on his shirt sleeves.
Continuity mistake: When the two station reporters are showing Eddie's drawings to George Waggner, the drawings change position on the desk between shots. (00:16:00)
Continuity mistake: After the 'game' of flying over the drawbridge in cars, Ginny runs away into the forest with just her scarf. In the forest she has her scarf and handbag.
Visible crew/equipment: When Dr. Boyle arrives in Boston, you can see the reflection of some crew members on the car.
Continuity mistake: About half way through the movie, the three main characters are in a loft. When the Asian girl grabs the postal worker's jacket, a cassette tape falls out of his pocket. As the girl bends down to pick up the tape, the camera shows here reaching with one hand, and then the camera switches to a close-up of her picking up the tape with the opposite hand.
Continuity mistake: Jack sees the car drive into the creek and runs to check for anyone injured. Jack dives into the water and you see the car submerge completely. Jack is then looking around and the car's trunk is sticking out of the water, then submerges yet again.
Continuity mistake: The actress playing Dolores is suddenly played by scream queen Linnea Quigley. The original was recast due to the actress having problems with the nudity, and shots of her were cut out as much as possible.
Plot hole: After the first murder in Pam's dorm room there should be blood everywhere but when Pam returns to change her dress there is only a single stripe of it on the bedsheets.