I don't think that fabrication is the best term to use. But what you might be thinking is a bit different from how things are done in Japan.
In Japan, you have to have some sort of approval from the ministry of education to do just about anything on a campus. If you want to start a karate club, you have to be under the direction of an orginization that they say is a valid system. You can't just get together with just anyone and make a form of karate up on your own and practice it on campus.
So I think that if you want to start a ninjutsu club at a school, Hatsumi is a teacher that you can associate with and get permission from to start it under. I don't think they really look much into the background and such. They mainly seem worried that you are not a cult and do things that might get someone killed through outright stupidity.
Mind you, I do not know the specifics about this particular case. But from working inside the system for many years, I would not put too much into the fact that Hayes is saying that Hatsumi is a recognized teacher. It is not that big a deal.
