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)
Factual error: Throughout the film, Lieutenant Choi and his platoon use a radio with a handset to communicate with their base. The radio however has an H-250 handset, which wasn't introduced until 1987, and the film takes place in 1972. The radio handset should be the H-189, which is the correct model for the Vietnam war from 1966 onwards.
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.