Questions on brandishing firearm

I don’t carry but my son does. He was explaining some of the differences in brandishing and how the laws work.

I’ve been known to be a hot head, but I would never brandish a gun in an argument, I’d probably be way more likely to diffuse the situation or walk away, which you are sort of expected to do.

My question is this, let’s say there is a situation that is going south, like a group of thugs or a crazy big guy and all you want is to go on your way. You don’t want to have the guy or group get to close where you can get sucker punched or tackled. Is there a big difference to pulling your gun and pointing down or at the person from a legal standpoint. Maybe the guy is walking towards you and you are retreating.

I’m sure laws vary wildly from state to state. I know here if a guy kicks you door down you are expected to retreat, you can’t shoot unless there is element danger to yourself or others