I have worked for a couple of different shops and the only place where I had trouble was working for someone who was barely even a diver. Running the shop they had no concept of safety, standards etc so we subsequently had a falling out. In my experience, being an instructor can help but as long as the owner is a diver so has understanding of the sport as a whole especially with classes and teaching it doesn't matter the qualification of the owner exactly. In your situation I would be a bit worried about why his license was revoked if that is the case.