In the supply scene, before setting out for the mission, the U.S. passport Dieter shows is not only the wrong color (blue rather than green), but is also the smaller size in use today rather than the larger size in use at the time.
When flying the Skyraider, Dieter Dengler (Christian Bale) is wearing a SPH-4 Helicopter pilot helmet that is missing it's visor assembly. In addition to missing a major portion of the helmet, this helmet was not in use during the time period of the film (it wasn't seen until the 1970s), and was not used by the pilots of fixed wing aircraft.
In the supply room scene, the sailors are shown with name tapes, and "U.S. NAVY" tapes on their dungaree uniform shirts. The US Navy did not use these until 1992. During the Viet Nam Era, Sailors either stenciled or hand printed their last name above their left breast pocket.
The SKS rifles carried by the Pathet Lao have had their bayonets removed, something not seen in a wartime rifle. However, many SKSs imported to the United States had the bayonets removed in order to make them legal for sale in California.
Shortly after being shot down, Dengler is seen randomly flashing his signal mirror in order to attract attention. The proper way to use such a mirror is to sight the rescue aircraft through the transparent circle in the center of the mirror, which then automatically aims the reflected light right at the aircraft.
The type of aircraft changed in the crash scene: Dieter
Dengler's aircraft was an AD-1 Skyraider. The tail section of the crashed aircraft in the rice paddy is most likely that of a North American AT-6 which has rounded vertical and horizontal tail profiles. The Skyraider has squared off tail profiles.
At the end of the scene in which Dieter is given the choice of signing the document condemning America, his glass of water magically gets refilled as he is taken away, and then goes back to its original level.
The aircraft Dieter took off in is not the plane he crashed in. As noted before, the tail section is not that of a Douglas design, but a mix of North American (AT-6) and something from Curtiss (the rounded elevators), and the rudder is fabric, as evidenced by the deformation wrinkles.
At 1:19:35 , when Dieter steals the rifles from the hut and approaches the other prisoners before their attack on the kitchen, a crew member (wearing a cap) can be seen moving from the right of the screen to the left with a camera or some other equipment.
Twice in the film Dengler is referred to as Flight Lieutenant Dengler. There is no such rank in the U.S. Navy, nor in the U.S. military. That's an RAF rank. Dengler was a Lieutenant Junior Grade, commonly called at LT JG (Lieutenant Jay Gee).
During his captivity, Dieter is shown wearing his gold wedding band - it is generally regard as something no American pilot would do. However, on the DVD Walter Herzog explains a deleted scene where Dieter's ring is almost stolen. When the guards are transporting Dengler to prison they stop at a village. A man there threatens to kill Dieter unless he gives him his ring-a gift from his fiancée. When they leave the village Dieter tells the guards his ring was stolen and they return to the village. The guards cut off the villager's ring finger and return Dieter's ring to him. This is a factual event that haunted Dengler the rest of his life.
When Dengler is rescued, he only lowers one prong on the jungle penetrator rescue seat instead of the two prongs as taught in survival training. This is explained in Dengler's book because he was "woozy and distant".
During Dieter's shoot-down scene, when the camera cuts to the
flight instruments inside his plane, the altimeter is shown winding down rapidly from 57,000 feet yet he's just above the ground. Also note, the 10,000-foot indicator fails to move at all AND the rate of climb indicator shows a slight climb.
The protagonist's funny and "inspiring" words at the close of the film sound like a Zen or Confucian quote picked up in captivity but, a) they were spoken first by an American (Alice Roosevelt Longworth, the daughter of Theodore Roosevelt), and, b) Alice didn't say those words until 1974, 8 years after Dengler was rescued.
When Dieter is finally rescued and in the helicopter, a camera angle from outside of the helicopter shows him holding a Butterfinger. However, the next camera angle from inside of the helicopter shows one of the soldiers handing the Butterfinger to Dieter, who looks at it as if it were his first time seeing it.
In the air to ground attack, the plane's 2.5" rockets are shown to be dropped like bombs; rockets are fired, not dropped. Even if the rockets in this instance were bombs, it would be rare for them to be dropped all at once.