When Eve Tozer tells Charlie Shane that she couldn't live without money after he told her that her father should be declared dead, she smokes a cigarette. In the next cut the cigarette is gone.
The wreck of first the deHavilland burned and the engine fell from its mounts. Both deHavillands were shown flying in the film and were powered with the V-8 Curtiss OX-5 powerplant. The engine seen in the burned airplane was an inverted inline 6 cylinder, most likely a Liberty 12A six cylinder.
When they arrived in Nepal, locals were clearly taking Myanmar (Burmese). Even Alessa was asking her mom if Bradley is here and her mom answer no and there were talking Myanmar (Burmese). Nepal natives have their own Nepalese language and no connections at all with Myanmar.
The destroyed airplane dropped its engine but the front of the engine compartment where the engine connected to the propeller was intact and showed no signs of compromise.
Aircraft from this era did not have wireless radios.
O'Malley's aviator glasses are of a shape first introduced in 1941, some 15-20 years after the events in the movie.
In the climactic battle scene, a number of the Chinese peasants can be seen using Mauser 98k rifles, a variant of the 1898 Mauser which wasn't introduced until 1935, at least a decade after this film is set.
Aircraft from this era did not have electrical starters.
In the scene where they escape from the Arab camp, a young Arab man claims he will kill himself if she leaves. Eve screams... well, originally it was just "Men!" and he lips clearly say more. But the sound is blanked out. Otherwise, I guess it would have been a 15!
Their "high road to China" takes them from Europe through the Middle East, Afghanistan, Nepal, arriving in China via the Tibetan highlands from the West. Using this route, it is impossible to fly over the Great Wall of China as indicated in the movie. The Great Wall is on the northern part of China.