Continuity mistake: When Bill and Jen go into Judith Myers's room, there is a camera angle from Michael Myers's view. There are two lit candles on Judith's dressing table where Jen is sitting, but in the next shot, Jen lights both of the candles. (00:38:30)
Continuity mistake: Sara slips and falls in a puddle of blood. When she gets up, her hands are all bloody. When she goes over and tries to open a door, they are clean. (01:17:05)
Continuity mistake: Just before Jen gets her head sliced off, Michael Myers raises the knife and you can see on the knife there is no blood on it, even after killing Bill with it. (01:01:10)
Continuity mistake: When the third knife is stabbed through Rudy you see it come out of the other side of the door but you don't see any of the other two knives below it. (01:04:25)
Continuity mistake: We see countless times that there is a wooded area behind the Myers home (especially after the house burns down, it is seen more clearly). But in the other films, the Myers home is in the middle of a residential neighborhood. Behind his house would be the back of another house.
Continuity mistake: After Sara and Freddy walk down the stairs after Michael Myers is hung, the curtain on the door behind Sara changes between shots, even when they peek through it.
Continuity mistake: When Jen's head is on the floor you see the view from her attached camera is facing Sara, Rudy and Jim but when you see Jen's head on the floor the camera is in a position where it is facing straight at the floor. (01:01:25)
Continuity mistake: When Michael first gets his head cut off by Laurie the eyes of the severed head are clearly wide open. (in H20 and in flashback scene) Then when they remove the mask from the head, not only is the mask suddenly and noticeably different, but the eyes are now closed.
Continuity mistake: When Rudy is in the kitchen, he tries to open a door but it's locked. After Michael pins him to that same door, he opens it right up and walks through.
Continuity mistake: In the garage, Sara falls into a cart with equipment on it. It tips over easily yet the equipment lands on Sara's leg and she's unable to move.
Continuity mistake: When Bill talks to himself in the mirror Michael bursts through the wall and grabs him but after you see the quick scene with Freddy and Nora having their glasses of wine Michael is completely out of the wall when he stabs him. (00:43:30)
Continuity mistake: When Freddy enters the kitchen dressed up as Michael Myers, he has a knife in his hand. Moments later, you see him yell at the real Michael Myers. Freddy has no knife in his hands and you didn't hear or see him put it down. (00:51:00 - 00:52:30)
Continuity mistake: Halfway through the film, we see Michael Myers walk into a room immediately followed by another Myers. Both are dressed nearly identically in a blue jumpsuit. But as soon as the first one turns around and we learn it's actually Freddie, the shot changes to Michael and back to him and he's wearing his jean jacket, seen in the rest of the movie.
Continuity mistake: When Michael Myers has Sara cornered, he rotates the knife in his hand so the blade is pointed down. After being knocked backward by Freddie, Michael advances forward and once again rotates the knife to point the blade down, yet he never changed it back.
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: 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: Nora picks up her phone twice before she makes the call to Freddy in the garage, whilst Charlie is getting killed.
Continuity mistake: After Sara receives a message saying that Michael Myers is still alive on her palm pilot Michael Myers stabs Freddy in his left shoulder but when it cuts to the close ups of the blade in his shoulder it is in his right shoulder. (01:11:45)
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.