Daniel Peterson wrote:
Had tales of his (perhaps temporary) apostasy never appeared, we would probably be saying about as many nice things about him as we typically say about his frequent co-author, the late Dr. Milton R. Hunter, a member of the Seventy whom we seldom if ever even mention. Ferguson and Hunter meant well, and they did some useful things, but they belong to a much earlier, much more naïve, and much less sophisticated stage of the LDS study of the history and archaeology relevant to Book of Mormon claims. Few if any people read them any more.
The difference is that he tended to avoid apologia and go with the evidence.
Thomas Stewart Ferguson, though, has been and continues to be exploited as a weapon against Latter-day Saint faith. I'm aware of no obligation on our part to be silent in the face of that fact.
Sure he concluded the church was not true, and it was not only based on the Book of Mormon. He may not have been honest enough to go public, but he was honest enough with himself.