The book “Out There” was a journalistic deep dive into the activities of the then-current “UFO Working Group”. I *think* (not having the book right here) that he was the one brought in to give a presentation on that earlier research, then sat down to join the meeting, but was then told to leave because the activities were compartmented.
https://search.brave.com/search?q=Col.+John+B.+Alexander
I believe I read that Blum book decades ago—probably have an old paperback around here somewhere.
There was and remains a lot of confusion about what is “official” .gov vs what is just “hobbyists” who happen to work for .gov.—and whether their “hobby” is a real hobby or just a cover story for whatever agency they work for at a time.
Compartmentalization and “special access” programs combined with disinformation along with a little sprinkling on con artists and deluded crazies has created a mess—true Alice in Wonderland stuff.