Other mistake: Watch the scene where the drunk Ben Tramer (wearing a similar Michael Myers mask) was hit by the speeding cop car and then pinned against the parked van before burning. Even taking out the equation of accidentally hitting Ben Tramer, what was the cop car doing speeding at that rate of speed, head on towards a parked van on a side street? Remember, we only hear screeching brakes after the car hits Tramer, and we never see the cop car swerve or any of that to miss hitting the van. Seems that even if Tramer hadn't been there, the cop car was sure to barge head on right into that van.
Other mistake: Right at the part where Crazy Ralph is looking in on Paul and Ginny. Ralph hears a breaking of a stick behind him. You can see Jason put the barbed wire up and over the tree. How is that possible? He would have to whip it around the tree, not over it. (00:30:20)
Other mistake: At the end after the barn fire, Marcia is at a tavern, ordering a rare steak. While it is believable that she escaped the barn fire, it is unbelievable that she is in the tavern wearing the same dress and necklace she wore prior to her transformation in the barn. All of her attire would have been rended in the transformation and lost in the fire. Unless her wardrobe consists of duplicates of the same clothing.
Other mistake: When the killer and the girl's body fall out of the window she's barefoot. Given she'd been dug up she should've been wearing shoes.