Once in a blue moon I see an actor holding a gun correctly. It’s way too rare.
When they are holding someone at gunpoint, it’s a trope, they MUST have their finger on the trigger. It’s more dramatic that way. That’s their excuse.
Hollywood willfully admits their dreck is not realistic, or fact but just entertainment. They don't care as long as people watch and it makes money. Most people are too stupid to notice, or care. Remember, you have a bunch of Leftist Soy Boys, Gays and Woman running the show. Guns? They are scared of them and most likely never even touched one in their lives.
I see this with aviation content also. They are clueless and don't even see the need to hire experts to show them how airplanes fly before they do the CGI for them. It looks like crap as does almost everything else related to airplanes and flying. Utter CRAP.