Continuity mistake: Near the end of the film, Deckard is communicating to Sara's handheld device where Michael Myers is in the house. When Deckard tells Sara to "GO NOW!", the text has changed from small digital text to large bold font and the screen has changed from green to white, similar to a large PC monitor.
Continuity mistake: Freddie has all the cameras cut when they find out he's a fake Michael Myers. When the kids complain to Deckard about it suddenly going offline, they tell him to bring it back. Deckard types at a fast rate, yet not only is there no dialogue box for text to be typed in, the screen remains the same.
Continuity mistake: At the Myers house when the guy with the black jacket is lighting a candle he uses his right hand then the left.
Continuity mistake: When we see Michael in the flashback with the security guard, he has on his mask from this movie, when it should be the Halloween H2O mask.
Continuity mistake: Jen's head lands at the bottom of the stairs. Later on in different scenes of the movie, it's obviously not there anymore because of all the running around downstairs and upstairs. Yet it's conveniently where it landed the first time because we see it on the monitor in the garage.
Continuity mistake: When Michael pins Rudy to the door, he uses the two knives that Rudy had in each hand. One of the knives goes clear through the door and out the other side. Michael then gets another knife from the drawer and it too goes through the other side, but the first knife that went through is now gone.
Continuity mistake: In the garage Sara falls down and a piece of electronic equipment lands on her. She acts like it's so heavy that it has her unable to move. Yet when Freddy comes to her aid, right before he lifts it off, Sara starts to get up on her own.
Continuity mistake: Throughout this entire film, the interiors of the Myers' house are huge, compared to the small two story frame house exterior.
Continuity mistake: Nora picks up her phone twice before she makes the call to Freddy in the garage, whilst Charlie is getting killed.
Continuity mistake: When Sara gets locked in the closet after the mannequin falls on her, we see Rudy's fist bust through the closet door, as if there were no other way it. In the next shot, the closet doors are wide open.
Continuity mistake: When Michael is walking towards Laurie's room in the sanitarium, the window on the door is yellow as if a light is on in the room. Then in the next shot it is blue as if a light was not on.
Continuity mistake: In one of the last scenes where Sara Moyer has a blanket around her shoulders. She has her palm pilot in her hand and she has just received a message from Berman saying that he can see her on the news. The very next second after reading that entry you can here the palm pilot shut so you know she a has closed it. Then the very next shot you can actually see her shut the palm pilot.
Continuity mistake: When Michael Myers is holding the tripod to impale the crewman, the length of the sharpened end changes in length and shape numerous times. First, it's wider and smaller. Then it's slightly longer and narrower. And when it's finally through the victim, it's long enough to go through the neck and into the adjacent wall.
Answer: Or maybe he's thinking that his mission to kill Laurie is done. He's been trying to kill her for a long time and succeeded. No need to continue, but when those kids invaded his house, the killing began again. No one goes into his house, but him.