Well acquainted with Mr. Prather here. Let's just say that he's got a poor reputation in some circles, and that's not even touching his military record.
I can check up on it, but I don't know if he's affiliated with the Bujinkan at this point. Also, dan rankings have been awarded just because some people have been around for a long time.
There were people under Stephen Hayes, whom severed their relationships with Hayes, and went back to train under Hatsumi. Others trained with Hatsumi a long time ago, but have not trained for years. So you have people claiming Bujinkan affiliations, but you have to look very, very hard to find evidence of it. You also encounter people that state they were given menkyo kaiden in specific ryu, or weapons - that should arouse suspicion in and of itself. That's one of the reasons you can go to a Booj class with five different instructors, and you are left scratching your head because they don't resemble each other. To further complicate matters, the different Shihan in Japan teach some things differently, and some practices have been changed by Hatsumi. Unless you train there regularly, or train under a person whom does so, you won't know the differences.
And where there is one douchebag misrepresenting himself, you often will have other douchebags that will vouch for him, often because there are multiple financial arrangements. One person might actually be sending dues in to the Booj every year, but collecting money from students who in fact are NOT registered with the Booj. Or doing the rounds on the seminar circuit. With the speed at which records are processed in Japan, you might be lucky to get your membership card in a timely manner.
Add to this stew pot, the attitude amongst the Japanese that a fool will find a fool for a teacher. It can all get very confusing.
There are many instances where an individual trained for a short period of time, and then a year later this same person claims advanced ranks in "ninjutsu" or "togakure ryu", etc.
Because of this rather outrageous climate - and the Americans are often singled out for this reason - people will either get turned off and leave, or become sidetracked by personalities who run things "their way". Warriorschool is by no means the only instance of cultish behavior associated with 'ninjutsu".