Considering you can't even by stock at a large firm without clearing it, I'm going to guess: almost nobody.
There is no way mlb knew about the nature of this business. Firms survive on reputation. Nobody hires a firm with a bad reputation for keeping client confidences. Why would the other partners risk their income so this guy's wife could make a buck? It makes no sense, especially considering how much money there is in representing apple as a repeat customer.