See Bill Presson's post above. It seems likely that he already is an owner-employee and that nothing special needs to be done...except that all prior tests were wrong.
Now, if the income is in fact being treated as passive income and he does not have self-employment income, then you have a couple of questions - 1) is that legit (see jpod's post), and 2) if it is legit, then why would it suddenly, for business reasons, be legit to change that? Having said that, I find it hard to believe that an owner has absolutely no involvement and absolutely no "earned" income from this venture. Paying him something would not be a stretch. But paying a partner on a W-2 is wrong, and paying him $0 accomplishes nothing, IMO.
It sounds like there are a lot of people involved who have a hint about things, but only enough to be dangerous. I'd start by finding out exactly how he gets paid and work from there.