Character mistake: When Sheriff Brackett is talking to Loomis at the food stand, he calls him Don. His name is Sam. Even says it in the subtitles. (01:19:35)
Suggested correction: He could possibly be saying "Doc".
No, he's definitely saying "Don." It's never been addressed, but I think it's an honest mistake with two people who have never met before and maybe an homage to Donald Pleasance, who played Loomis before.
It's hard to say, but it does sound like "Don." The sheriff says "doc" two times later in the same scene and those two times definitely sounds different than the first time. But I don't think it's meant to be a homage to anyone. I think it's just an actor who flubbed the word.
Other mistake: In the original ending, after Laurie is pulled out of the cop car, Loomis is able to reason with Michael to let her go. After he does, he is shot to death by the police. This was obviously changed, but when Loomis is reasoning with him in the final cut, you can still see the police standing behind him. (01:46:00)
Suggested correction: The police came anyways. He is a wanted killer, after all.
During the timestamp above, an officer standing behind Loomis with their gun ready while he's talking to Michael, but besides these shots, the officer is nowhere to be found. In the alternate ending, this confrontation is completely different as cops are shown actually pulling up behind Loomis. You are able to see that shots from the alt ending are used in the final movie, thus making the mistake valid.
Plot hole: Laurie calls the police from 1987 Winchester drive, and gives them that address. Yet the police responding to the call go directly to 1960 Winchester drive - where Laurie has run to and is now hiding - even though it's on the other side of the street and several houses down. (01:31:30 - 01:33:40)
Suggested correction: Initially Laurie sends Lindsay across the street, back to the Doyle house to call the police. It's possible Lindsay gave the police the Doyle's address (since that's where she was calling from). Since that call was likely made before Laurie made her call, that explains why the police first show up to the Doyle's house (responding to Lindsay's call) and Bracket shows up minutes later at the Wallace's house (responding to Laurie's call).
Stupidity: When Michael goes to Judith's room, all she says is, "Michael, what are you doing in here?" She doesn't even ask why he's all bloody.
Suggested correction: It's Halloween, and she most likely thinks he's got into the spirit. Let's also not forget how she treated him earlier when she blew off taking him trick or treating. It's obvious she doesn't care about him at all and is beyond self centered so it's not surprising she wouldn't comment on it.