When General Moore tells Greg who he is, Greg is skeptical of his identity, however, in later episodes they are portrayed as long standing friends, even knowing each other in Washington D.C.
In the first dog fight when Boyington goes up against two Japanese Zeros, there are several brief cockpit views where the bandage on his left cheek moves to his right cheek, and then back again to his left cheek.
In the dogfight over the mountains, the fuselage of the second Zero is white, then dark, then white and finally dark as it burns in.
Fleet Admiral Chester Nimitz' son Chester Nimitz, Jr. was a navy officer in the Pacific Theater (winning a Navy Cross as a submarine commander). However, his nickname was "Chet," not "Teddy" as both Boyington and Nimitz suggest during their phone conversation.
Colonel Mathys, an army officer assigns Boyington to Esprito Marcos. Army officers would not be in charge of personnel assignments for US Marine Corps officers during World War II.
They have Admiral Nimitz at an office in the Pentagon, the only trouble was he was at Pearl Harbor during World War 2.
As a Flying Tiger, Pappy and all of the Tigers are shown wearing A-2 flight jackets. With the exception of General Chennault, all Flying Tigers were issued M-422 Jackets, known today as the G-1 Jacket. It wasn't until after the Flying Tigers were disbanded and renamed the 14th Air Force that they were finally issued A-2 jackets.
The General states that Pappy is 35 years old. When he rejoined the Marines as a Major, he was 31 years old (born in 1912).
Near the beginning, when Boyington shoots down the second Japanese fighter, black smoke begins to pour out of the left side of the aircraft. Instead of the smoke trailing behind the plane as it moves forward, the smoke hangs in a cloud next to the plane indicating that the aircraft is sitting still in midair, which is an impossibility.
Boyington is lying on his cot reading the files on three pilots (Gutterman, Bragg and Wiley). With the exception of their names and ranks, all three files are exactly the same, word for word.
Pappy calls Admiral Nimitz during a conference in a clearly complete Pentagon immediately following Pearl Harbour. The ground breaking took place only two months previously, and entered into use two years later.
As 2 Zeros are jumping Pappy as he is on way to Pacific you can clearly see the contrails of a passenger jet in the background.