Getting good gun information from TV shows is like getting good information on the laws of physics from Bugs Bunny and Roadrunner cartoons.
One show I saw had a detective pick up a 9mm empty at a crime scene, glance at it, then state that it was fired from a Tec 9. I had a Tec 9 at the time, and so I checked. There are some guns that leave distinctive firing pin marks (like Sigs) The Tec 9 is NOT one of them.
Another show, one of the NYC Law& Order ones, had someone shooting a Desert Eagle with a 15 shot magazine. That mag doesn't exist. And when the detectives informed them that 15rnd mags are illegal in NYC, they said, "oh, I didn't know", handed the cops the magazine, then left.
Any show with a historical setting that shows us private personal conversations and character's "inner thoughts" is essentially making it up. And when the writers are making it up, they can make up about anything they feel like, accurate, or not.
I was trained by the military to repair machineguns. From the M16 to Ma Deuce (M2 .50cal) I tell you for a fact that working the action and the trigger ONCE does not, and can not tell you if it is functional full auto.
there are only two possibilities with that scene. #1) the writers know this, but the character they are creating does not, and so makes a BS statement.
#2) the writers do not know this, but think they do, and so the character makes a BS statement.
You decide which is most likely...
Either way, same result. In a way, its like lying under oath, about a little thing. Once you get caught in that ALL your credibility is suspect at best and completely gone at worst.
Some might say, its ok, if they get the little stuff /technical items wrong, as long as they get the big stuff right. I say, if they get the little stuff wrong, how can they be trusted to get the big stuff right???