Braddock was tortured when POW in flashbacks. He has no visible scars when he removes shirts throughout film.
It's never shown or explained how Braddock survived his suicide jump with two hand grenades. Such an action would certainly obliterate both him and the NVA he jumped at. Next scene has him as a POW, seemingly unharmed, and has the strength to carry a man on his shoulders.
When Braddock returns to Vietnam, the capital of the country is referred to as Saigon. After 1975, Saigon's name was changed to Ho Chi Minh City.
The Bangkok, Thailand setting featured motor vehicles which are left-hand drive; motor vehicles sold in Thailand are majority right-hand drive.
The Vietnamese officials use the term 'People's Republic of Vietnam' - the official name in reality is the Socialist Republic of Vietnam since July 2, 1976.
When Braddock rigs the grenade to fall after the jeep is moved, the enemy jeep hits it and dislodges the Grenade. There two separate explosions that shoot up from the ground as the FX explosions were set off.
Jack Tucker is thrown off of a second story balcony and lands on someone's dinner table, complete with food. When he lands, only his back is visible. After a cut, he is shown getting back up and his face is now visible for the first time. However, he landed on a big plate of food yet there is no food on his shirt. Obviously, it was a stuntman who fell and then M Emmet Walsh was substituted after the cut.