If one reads the cited thread on the LF Forum, it was plainly evident that it was started on a totally preposterous aalegation. The originator claimed to have noticed a pattern in Ryan's auction site buying and selling. The assumption made was that Ryan bought Ansel Adams negatives, then shortly after, marketed prints made from those negatives as original Adams prints. There was never any more evidence offered than this singular assumption.
Why someone would make such flawed allegation is beyond me, but it happened. I suspected the original thread was started by a troll for whatever reasons trolls start vengeful threads. That leads me to suspect Mr. PhotoHistorian may be connected to whomever started the LF Forum thread, because how could one say what he said if one actually read and understood the original allegation?