Continuity: The wall behind Michael changes as he takes the gun away from Brady. First, there is a solid wall with decorative hangings, then there is a shot of the front door, then the solid wall again.
Continuity: Michael reaches into the truck and rips Rachel's sweater, but in the following scene, Rachel's sweater miraculously returned to normal, buttoned and all.
Crew or equipment visible: The cameraman is reflected in the window when Dr. Loomis runs to the window to look for Michael.
Continuity: Michael's full name is Michael Audrey Myers yet in the mental hospital when someone is typing his name on a form they write Myers, Michael M (possibly character error).
Continuity: Michael's hair from the mask changes from straight messy brown, to full curly blond when Loomis is thrown into the glass doors.
Continuity: When Dr. Loomis parks his car outside of the filling station, he stops past the last gas pump. The next shot shows his car much closer and he tries to fill it up.
Continuity: As Rachel and Jamie slide down the roof, they look down and a bike can be seen on the ground. When Jamie ends up running to Rachel later on, the bike is no longer there.
Revealing mistakes: If Michael was shot in the eyes in Halloween II, why are his eyes intact in this one?
Continuity: Rachel's purse disappears and reappears when she sees Michael and runs from him, while she is looking for Jamie.
Continuity: When the camera is at Michale's back once he get hits by the truck the truck is stopped, but in the next shot the truck is still moving.
Continuity: The blue sedan Dr. Loomis parks at the pumps outside the gas station is different than the one that blows up minutes later in the same location during a fire. The vehicle he parks is a 1982-1983 Chevy Malibu with four headlamps and one kind of grille. The vehicle that explodes in the fire is a 1980-1981 Malibu with two headlamps and a different grille.
Plot holes: Michael got his overalls from a mechanic he killed by impaling the guy with a metal rod in the chest area. Yet there is no blood or holes on the coveralls.
Continuity: The burn scars on Dr. Lommis' face change periodically throughout the movie. There is a dramatic change from when he is riding in the truck with the preacher on his way to Haddonfield compared to when he arrives and comes into the police station.
Revealing mistakes: When Michael is in the ambulance car after he grabs the guy on the head he sticks his thumb in his forehead, and on the left you can see the end of the fake arm.
Revealing mistakes: In every scene before he is shot at or struck, it is obvious that there is protective padding under his coveralls.
Errors made by characters (possibly deliberate errors by the filmmakers): In the second to last scene, the character of Rachel refers to the character of Jamie by her real name Danielle.
Plot holes: When the girls are racing out of town with the mob and flag down the state police, there is no place for Michael to hide: 2 men are in the bed, under the truck is empty and both sides are clear and the state trooper watches them drive away yet he climbs in over the tail gate. Where was he hiding?
Factual errors: The scene where Michael Myers hides (laying down in the back seat) of the police cruiser in order to get a ride/locate his niece: After the police officer parks at Sherriff Meeker's house, and then returns to his cruiser, the backdoor (where Michael was hiding) is wide open and Michael is gone. The "goof" is that the backdoor of police squad cars do not open from the inside, for safety reasons. In order for the backdoor to be opened, Myers would have needed to climb over the front seat, exit the vehicle, and then open the backdoor. (Incidentally, while the backdoors only open from the outside, many of the older police cars actually required keys to open the door.)