To his credit that's a true scientist. As far as evidence goes other people's opinions are low on the totem poll of acceptable evidence, but faced with overwhelming evidence he was forced to reexamine the anecdotal for correlation which he found and through his new lens was forced to accept. His response in writing his book and presenting his findings is the final step. I can only imagine given his condition how hard it was to accept the truth, but accept he did and the world is better place because of it.