I don’t know where you are. Where I am, a permit does nothing for your liability. It will NOT “cover your butt.” As a matter of fact, it does nothing at all except cost money.
In new construction, we have to have them. In most tenant improvement projects that I work on, we also have to have them. But for residential stuff, I almost never pull them.
In my contract with my clients I state “Permits are to be obtained by others.” I definitely make the owner of the property where of this fact. That way it’s on them. If they do choose to permit, I add in extra time for inspections and possible corrections; or, I will make them sign on a work order “Permit and permit related issues including inspections are billed on a time in materials basis only, therefore, these charges are unforeseen.”
All of my work is to code. But the odd inspector will ask for odd things from time to time. I have found most of the time that it is simply easier to correct whatever they want rather than fight with them. If someone wants a permit pulled, that’s fine. But it’s gonna cost them my actual time.