Factual error: As the 1st Battalion, 7th Cavalry lifts off from LZ X-Ray at the end of the battle, it can be seen that there are no more American troops left at the battlefield. However, by the time 1/7 CAV left LZ X-Ray, it had been relieved by two full battalions (2/7 CAV and 1/5 CAV). There were around 700 American soldiers occupying LZ X-Ray by the time 1/7 CAV lifted off.
Factual error: Many shots of the submarine in drydock show Halifax, Nova Scotia's MacKay and MacDonald bridges in the background.
Factual error: One of the members of the orchestra is reading off sheet music held together by sticky tape, which is an anachronism.
Factual error: Part-way into the movie there is a scene where Ivan Cooper is walking up the road towards a crowd of people. On the road between him and the crowd are speed cushions, (a traffic calming feature to slow vehicles down). Back in 1972 speed cushions did not exist, they are an invention from the early 1990's. (00:39:00)