Corrected entry: Sheriff Bracket put Laurie in a foster home "off the books", so officially by all accounts Michael's baby sister was dead. Yet Michael not only knows she's alive, he knows exactly who she is despite not a single shred of evidence or police report to support it. (This starts to go into the old Halloween mythos that Michael subconsciously knew because of his 'curse', but in the context of Zombie's film being a standalone project, it doesn't fit).
Corrected entry: When you see Michael on the balcony, a couple arrive at his house thinking it is empty. As the van backs into the driveway you see a shape of a head in the rear windshield, then it quickly moves.
Corrected entry: When Tommy and Lindsey approach Dr. Loomis and tell him Michael took Laurie, we see him running down the street towards the Myers house. But later on, he brings Laurie outside into a cop car and starts it up. Where did the car come from, and if he didn't drive it there, why does he have the keys?