Continuity mistake: Right at the end, as Alex and Luke are about to have sex, Alex takes her hair out of her ponytail style and lets it hang down loosely. Her hair is extremely 'poofy' at this time, sort of messy as well. The camera angle changes to Luke for two seconds, then back to Alex. Suddenly, her hair is combed down and straight now...with no 'poofyness' and no hair out of place.
Other mistake: The DVD release was created with a "pseudo widescreen" as various scenes cut off major action. The most obvious is in the beginning of the film when the main character meets the crazy girl. Her head is framed bottom right but the widescreen completely cuts off the crazy girl's head. This can be explained by the enormous aspect ratio of the original film, which is bigger than standard (USA) widescreen, that or a bad transfer.
Continuity mistake: Throughout the movie, Cottonmouth Joe's horse changes from a tan Arabian to a black Clydesdale during attack sequences.
Deliberate mistake: When Brody confronts and then flees from the Headless Horseman, the horses never break into full gallop (it's little more than a stiff-legged canter), which is odd for a life-and-death chase with the bloodthirsty Headless Horseman in murderous pursuit. This was probably done on purpose, for safety reasons, since the actor playing Brody was performing his own stunt riding at night. To cinch the illusion of a real chase, audio was added of a 4-beat gallop.
Continuity mistake: When the protagonist goes to the mental institution and meets her former classmate now plagued by asthma and violent overacting, a wisp of hair on the forehead changes position between shots a couple times during the scene without her touching it or moving. (00:46:25)