He was a sole proprietor CPA. Do you really think sole proprietor's are able to/or care to keep up to date on all the "nuisance" compliance requirements of being a CPA? It's a big, time-consuming task (I know I'm a retired CPA).
Dwayne, the reality is small proprietors are not perfect and put more time into generating revenue from clients, than external compliance oversight. That's the real world.