Very interesting and professional discussion.
May I make a further suggestion?
Since it seems that often the authorities don't want to get involved (or perhaps get too involved with some folks they really don't like), why not take it up with the insurance company?
They would probably like to know how close to the line their clients are operating, as it obviously affects the risk the insurance company is open to.
Sending letters to both the authority and the insurance company might be a way forward. Of course, if you are concerned about being branded a whistleblower, you might get the letters sent by a lawyer - "My client, who wishes to remain anonymous, etc..."
Might cost a bit of money, but if you draft the letter for the lawyer it might not be too expensive.