So go out and sign Tom Crabtree again.
This is a fairly significant incident, and we're not talking about protecting a Nelson or Cobb or Lacy. It's not just the firing of the gun but the fact that the report definitely makes it sound like he was harassing a car full of women which in this day and age adds another degree of negative image to the incident, even if he's just charged for firing the gun. Quarless isn't nearly a special enough player or important enough part of the offense to ensure that he won't lose his job over incidents like this.
There are a couple vets like you named, they could bring back Crabtree, they could take a flyer on Lyerla again and see if he pans out in TC, or scour the waiver wire after final cuts this year. None are great options, but depending on what happens we may be looking at losing Quarless for a significant amount of time anyway.
I'm not saying for sure he'll be cut, but I definitely wouldn't go as far as to say there's no way it happens.