I had to laugh when I read this as you're doing exactly what you accuse Fuhrman of doing.
At any rate, he had access to people and documents they we haven't had.
Why would he have access to documents, he wasn't on the case. There is such a thing as patient privacy, no where during this horrific ordeal was it mentioned that he was involved in a investigative manner. If his book is speculative than we already have and read all the speculations of what happened, here on FR there were VOLUMES written.