Hashgahot

Question

You have written that if you will eat in someone's house, you can also eat in his restaurant, and in truth, you don't even need a hashgachah. But what about if you will eat in the mashgiach's house, do you also say that you can trust his hashgachah on the restaurant? It would seem that this would open a can of worms, because there are some very religious men, in whose house everyone will eat, but they also give hashgachot to what appear to be very questionable restaurants. It's possible that people will cut corners in order to make money where other people are concerned, but will still keep a glatt kosher house.