That's not true, he was board certified by an existing board, but created his own (never accepted by anyone that matters, apparently) board to fleece other doctors, or, nominally, at least the first time, to protest the board he was certified by. He then let it lapse by failing to file paperwork, reformed it years later, and let it lapse again.
I have to wonder if it being his father's medical school also was a factor, considering it's a private school. But still, that's quite impressive.