At the end of film when Crocker finds Young in his room, he picks up a gun off the floor and puts it in his right coat pocket. Major Dunham then knocks on the door and Crocker turns to face him, but the gun is no longer in his pocket.
When the plane lands upside-down early in the film, Young and Crocker climb out and are then sitting beside the plane. Crocker takes off his leather flying helmet. The film cuts to Young, then back to Crocker, who now is wearing the flying helmet again. Another cut to Young, and back to Crocker, and the helmet is off again.
At end, Jerry is referred to as a captain, but throughout the film he had two pips on his uniform which is the insignia for a first lieutenant. A captain is three pips and a major is a crown.
When Major Dunham enters the room with Jerry Young lying on the bed, a suicide by a shot to his head,, his head covered by Henry Crocker, Crocker goes along with Dunham's false impression that Young is only passed out. But the smell of gunpowder should still be fresh in the air. although Dunham shows no sign of detecting the smell, deluding himself that Young is only asleep.
All the airplanes except the DeHavilands are well past 1918 time period. Curtiss P-1s are recognizable as well as other airplanes with highly tapered wings. Even the DH-4s were dated by 1933, but had been kept around, first as mail planes, then as barnstormers.