I don't know much about the controversy surrounding Scott McCarron and Phil Mickelson but it sounds to me like if Phil's clubs are approved, then that would be that.
I don't know why there's such an uproar about this apparent conflict in rules vs approval of clubs etc. In the real world where most of us have bosses, we have this kind of thing all of the time. The organization tells us what the rules are, but individual bosses interpret the rules however they want on any given minute of any given day. We mere working folks have to deal with the ever-changing 'interpretations' and still keep our jobs. If we call people cheaters and whine about the application of rules, then we risk our livelihoods.
And frankly, the bottom line is, McCarron should go get him some of Phil's clubs if he thinks they are so much better than the equipment he's using. He knows he won't get booted out of a tournament for having them.