Other mistake: Garcia, in a manic moment, dips his right fingers into the bug's acidic saliva, then stripes his left cheek, where the acid eats into the flesh. A couple of minutes later, he dips the same two fingers back into the substance, and proceeds to stripe his right cheek, where the acid immediately starts eating through his skin. Oddly enough, the fingers aren't affected at all, despite being dipped into the goo twice.
Other mistake: Marvin survives the explosion by hiding in the refrigerator, though despite the massive blast, there is no singeing, burn marks, or even smoke around the holes that were torn into the front of the door before the explosion.
Other mistake: When Jason is in the corn field during the rave, after Jason breaks the guys neck, the other guy burns him with a torch and the flames burns around his neck area, which should have caused him to not have any hair. But throughout the movie, his hair is still there.
Other mistake: When Kimberly gets in the ambulance at the hospital to drive it into the lake she shifts it upward instead of downward to go from park to reverse.