Other mistake: When the main guy and the blond-haired woman investigate the house of the guy who got hanged in the very first scene, October goes outside to smoke. She is seen in a construction site. Later, when they go to find October, we discover that the site is way down the street. I don't know why she decided to stray so far from the house to the site.
Other mistake: When October uses the nail gun to try and ward off the evil woman, she points and shoots it like a normal gun. However, as a safety precaution, nail guns have a mechanism that requires it to be pressed against something in order for it to dispense nails. Therefore, October couldn't have used it like she did.