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Stock sound effects are comically misused sometimes. I think my favorite was in one of the Schwarzenegger movies (True Lies?) a helicopter (with no wheels) lands kinda hard, and you hear a car-tires-screeching-to-a-halt sound.

Also not really an error, but once you recognize a stock sound effect, you'll start hearing it constantly. Like every single time someone sits down to eat, they make the exact same silverware-clanking-against-the-plate sound (especially in shows like Chopped - every time the judges go in for a bite, same clickety-clank.

Empty casings not being ejected from guns. It doesn't even need to be shown - just splice in a sound effect, FFS!

Medical and psych. The beefy male orderlies in white tackling people. 10% of the time it’s like that, more so on a child or adolescent unit, but mostly it’s hey, let’s go talk over here about your feelings and come up with better choices and that works. Being heard, works. Most of the time, the orderlies wear street clothes. The shot is real but it goes in a muscle not the neck.

Sprinklers reacting to smoke - they react to heat.

All sprinklers going off at the same time - only the ones affected will.

The water spraying out is clear - it's black sludge.

A plumber using a huge wrench under the sink, usually working on the p-trap and then water starts spraying - you don't need a big wrench for that job and there is no pressurized water inside sewers.

Archers effortlessly holding their bows waiting for the command to all release at once - the draw weight of a war bow is so immense that you're physically unable to hold it for more than seconds.

I'm in IT. It gets comical.

People make plans to meet and never go over the details.. like a time, or a place. It's always missing some critical information you would need if you were actually going to meet someone

when someone is on a phone call on their mobile the screen is not showing the call screen.

Cups, too. Coffee mugs or other opaque containers will sometimes be used to gesticulate, and you can just tell from the way they move it that there's obviously nothing in it. They can't get away with it when the glass is clear, but if it's an opaque cup, more often than not it's completely empty and the lack of weight to it gives it away.

Daredevil: Born Again - Subway platform with no security cameras.