Continuity mistake: In the opening scene, Gunnery Sgt. Hartman is making his speech and passes by Privates Cowboy and Joker on his way to the other side of the barracks. On his way he passes Private Pyle standing to the right of Private Joker. Later in the scene, when he rushes over to confront Private Joker and then moves on to Private Cowboy and then Private Pyle, Private Pyle is on the left of Private Joker. (00:02:00)
Continuity mistake: When Hartman is messing with Snowball, Joker quotes John Wayne. Hartman seeks out who said something. He grabs Cowboy by the blouse and pulls it upwards forcefully while questioning if he made the joke. Then Joker admits to making the joke. Hartman moves over to Joker, but you can see Cowboy's blouse is now bunched up at the top and no longer properly tucked in. After Hartman reprimands Joker, he moves back to Cowboy. Cowboy's blouse looks as if was never touched by Hartman. (00:03:40 - 00:04:40)
Answer: It was Gustav Hasford's idea. It happened in the original book that the story is based on, "The Short Timers."