Nah, I get what you are saying. Yeah, there are some places where the owners or friends of the owners act like they can do whatever they want. I worked at a place where someone would go into the kitchen and start yelling at the cooks after he had a few. But to add what you were saying, yeah, you'll sometimes get people bitching about how you aren't pouring a Guinness properly (which, admittedly can be true for some bartenders), or that you're making a cocktail wrong, etc. and they'll piss in your ear about how to do your job.
But folks jumping behind the wood during regular service? Not tolerated at any place I've worked at. Even staff who are off duty it is generally frowned upon.
There are places where people will drink after hours. Staff will sometimes have a drink or two and sometimes friends/regulars will hang after close. Very common in smaller towns/rural places where there's less oversight.
A lot of jurisdictions it is risky to do as if you get caught for that you can get into shit with the liquor board.
This is kind of a good example of a friend of the owner getting a place into trouble in my neck of the woods (spoiler warning: jeets ahead):
https://decisia.lexum.com/aglc/dec/en/item/423925/index.do
