Mik,
I know you don't like Mr. Payton and it appears to gall you that it may turn out that he is right, but continuing to question his motives is barking up the wrong tree. He didn't leak his report.
Remember, there are several universities, a couple of government agencies and several insurance companies involved in the investigation. Lots of people, with lots of friends, is how stuff like this gets out. I got my copy from a friend who got it at the antique construcion equipment convention. The steam and antique equipment grapevine is incredibly extensive!