When the Huey helicopter crashes into the house, the resulting explosion/fireball consumes the room. However, in the next scene, all of the wood and books surrounding the helicopter are untouched.
When the trucker is with his dog after Claire has left, the dog bites the truckers left hand but in the next cut he is holding his right hand in pain.
At various times in the movie, the actor's breaths would condensate as if it's cold. The movie takes place in September in the Midwest, which would be too warm for breaths to condensate.
Bravo team's police car, numbered 116, which is found upturned near the mansion, is also seen later in the police garage when the police chief is running from the dog.
Claire doesn't actually pick her brother's front door lock. She puts a knife to the seam of the door and frame well above the actual lock.
The motorcycle skid sounds like a car (multiple tires), but ANY skid sound on a wet road would make no sound.
Following the helicopter crash in the library, two of the characters not only survive the fireball, they stand and casually chat in a room full of flames and debris. The room is suppose to be full of heat and choking smoke, yet they act like it doesn't exist.
In the pitch dark mansion dining room, the approaching zombie's screams are instantly interrupted by silence whenever the flame from Chris' lighter goes out, and then the screams instantly resume when the light returns. While this is obvious artistic license, for the record the level of darkness would have no bearing on whether we can hear the zombie screaming.
A keyboard is seen with a key bearing the Microsoft Windows logo. Such a keyboard wasn't introduced after the time in which the movie is set.
While the helicopter pilot is waiting for the rest of the team, he's playing the "Snake" game on a Nokia phone. However, the model being used (a Nokia 5125) wasn't released until December 1998, while the movie is set in September 1998.