It is a violation but not one that will never be found unless they open a permit for something else. The NEC process pretty much stops when the customer moves in and closes the door. The best hope is an insurance inspector sees it before it is a fireman on a run.
I'm surprised but it might be that more states are actually requiring more training and certification for Home Inspectors. It used to anyone with a flashlight and a clip board could call themselves a home inspector.