The 'rockets' fired by the Viet Cong are actually air-to-air missiles.
Tracer rounds are only issued to machine guns; they are not usually used by other small arms.
There is no 7.62mm N.A.T.O. round.
There are two sizes of 7.62mm Warsaw Pact ammunition, not one: one is for handguns and submachine guns, and one is for rifles.
The M-67 is a recoilless gun, not a rocket launcher.
The A.I. is noticeably buggy, with friendly NPCs not noticing and firing upon enemy NPCs only a few dozen feet away.
NPCs sometimes spawn from places that the player is looking at.
Wrong reloading animations for the weapons.
Since no soldier carries partial magazines around, the maximum ammunition for each weapon should be a multiple of the maximum capacity of the magazines for that weapon.
Letters sent from Viet Nam to the U.S.A. were censored during the Viet Nam War. Shepard undoubtedly knows this, yet his letters include information about missions.
Other NPCs keep telling Shepard what to do even when he is promoted to Sergeant.
Sergeant Shepard's father says that he will only have to wait a few more weeks until his son is safe, when Sergeant Shepard has but a week to go.