Factual error: Doug Masters and his friend Reggie would be grounded on the spot and have their pilot's licences suspended (and in all likelihood cancelled) after buzzing the motorcyclist. Their flying is grossly unsafe. They would be visible for miles flying well below a safe altitude, but even if they were not seen their radio traffic and radar tracking would tell the authorities everything they needed to know.
Continuity mistake: In the scene where Bunny kills the one legged Vietnamese with the butt of his gun, watch the cigarette in Sgt. O'Neill's mouth. In a shot after the kid is dead, the cigarette in O'Neill's mouth is short. When it shows him again, the cigarette has mysteriously grown. (00:50:00)
Factual error: Calendar date at the very beginning of the film (in the police station), shows the dates of Saturday 20th/Sunday 21st July 1983. However the 20th and 21st July 1983 fell on Wednesday and Thursday.
Continuity mistake: The film is supposed to take place in 1917, but several of the german soldiers our heroes encounter are armed with Bergman M18 sub-machineguns which didn't appear until a year later. To make things even worse all the guns comes with a magazine-type that didn't appear until the mid-thirties.