When 1LT Tyson is in his Class A uniform, his Cavalry branch insignia is upside down. The crossed sabers should be pointed up, not down. Additionally, his ribbon rack is completely out of order. The Silver Star should be on the top row, left side. Then the Bronze Star, then the Purple Heart. Also incorrect are the rank and branch insignia on every actor while wearing the Battle Dress Uniform, or BDUs.
In an early scene at the hospital in 1973, a soldier is shown wearing a web belt with a green plastic buckle, which did not enter service until at least the 1980s. All web belt buckles during Vietnam were metal.
In the Viet Nam scenes, the soldiers were using M14 rifles, which were only used by the US army for a very short period, about 1965/66, before being replaced by the M16.
Tyson is on the base awaiting the court martial and assigned duty of mowing grass. It is obvious the mower is electric by the dangling extension cord, BUT the sound coming from the mower is that of a gas engine