Why would you retrospectively assume they weren't true? I would have assumed that one of the world's biggest Paph breeders would acquire the best plants for breeding purposes. Sam actually spoke at our society meeting many years ago. He told the story of how he acquired lowii 'Grand Masterpiece' that had won grand champion at the World Orchid Conference. The owner didn't want to sell it, but Sam ended up making an offer the owner couldn't refuse. Sam said as a leading Paph breeder, he had no choice but to get the best plants to breed with, no matter the cost.
I am not saying these TON roths from OI are legitimate. In fact, I am now very skeptical myself. But I also would have expected he would have acquired the best roth clones to breed with.