Other mistake: Max says that Michael is the "Man of the house" and won't come in until he's invited, which Michael sarcastically does, except Michael isn't the man of the house - its actually his grandfather who owns it.
Other mistake: When Taryn turns into a punk and walks down the alley way, you can clearly see Freddy's back along the bottom of the camera shot as if he is trying to pass the camera for the next shot. This happens as Taryn looks down the alley. However, if that was meant to happen, wouldn't she have seen Freddy, and not have been so scared when he approached her from behind?
Other mistake: The coroner examining the bodies in the tennis hall, he says that "lover-boy" is being "fished out of a swimming pool full of blood". But as he himself says later on, Pete was killed when his neck was snapped, there were no wounds he could bleed from. In addition, the zombie dropped him in a hot tub, not a swimming pool.
Other mistake: During one of the early investigations of the murder in the record store, there is a scene of the FBI agent and the detective in a Porsche driving through an intersection, almost crashing into a yellow car entering the intersection and swerving away to avoid an accident. Later on in the movie, there is another scene of the Porsche going through the same intersection, at a different angle, and almost hitting, again, the same yellow car, at the same position, doing the same manuever to avoid a crash.
Other mistake: When Evil Ed picks up Jake and throws him headfirst into the lightbulb, watch the speed that he hits it and then falls away from it; he moves far to slowly.
Other mistake: The werewolf gets blown to pieces by the dynamite, clothes and all. I can understand how the werewolf can reassemble his body as only silver can kill him. But how in the world do his clothes knit themselves back together?
Suggested correction: It was a nod to the comment Sean made earlier in the movie about Wolfman wearing pants in the 40's so you wouldn't see his "wolf dork"; it was meant to be a joke.
Other mistake: When the Predator sees Billy on the log bridge, there is a cold blotch in the middle of Billy's chest. He's not wearing anything that would make such a hole in his heat signature - it should be the same color as the rest of his torso. It doesn't even match up with the cut he made across his chest; the cut starts much higher than the blotch and the blotch is irregularly shaped, not indicating the smooth line of a cut. (01:15:20)
Suggested correction: The cold area is the blood running from his wound. It is cooling down on contract with the air.
Other mistake: Despite the noise of the demon in the house, the tornado clouds outside, the flashing lights from the demon exploding and the fireworks in the sky - not a single neighbor is anywhere to be seen. Even after daylight breaks the neighborhood is a ghost town as we pan away from the actors.
Other mistake: As the blond punkee pillages the bedroom for anything of value, the unseen giggling/squeaky "doll" voices prepare to attack. She is yanked to the floor by her feet, screaming, as the unseen grab her hands, then proceed to "ram" her face-first into the wall. The large blood spatters do not match the injuries to her face nor her forehead. Also, under normal circumstances, the victim would be rendered unconscious following such force. The punkee is merely a bit disheveled as the unseen toss her outside the doorway. (00:30:50 - 00:31:35)
Other mistake: When Ricky confronts the mother superior in the dining room, Ricky raises the axe above his head and brings it straight down in one single motion. Both Ricky and the mother superior are facing each other. At that angle, it would have been impossible for Ricky to decapitate her. At best her head would have been cleaved in half, but not decapitated.
Other mistake: The film is meant to be set in the US, but there are some odd lines of dialogue that seem to indicate the movie takes place in the England, such as a reference to the (very British) Julia being on her "home turf." This is the result of a change made in post-production, where producers decided to change the setting to the US to make it more marketable to American audiences. Unfortunately, there were some lines about the original English setting that (evidently) couldn't be cut around.