I know nothing about Lt. Col. Friend personally, but I do know being assigned to command Blue Book was what's known in the military as a "retirement assignment." It was assigned to officers who had been passed over for promotion and would have to retire or who were going to get out of the USAF. They were not the "best and brightest," I remember reading no Blue Book commander was ever promoted out of that job. The last few Blue Book commanders were particularly not highly thought of by their peers. I know this as I worked with many of them early in my career.
I still believe the USG "cover up" of UFOs is they don't know anymore than the rest of us about the 5-10% of sightings that are truly unknown. Unquestionably they know about the sightings and have collected data/information we'll not see, but as to what they are or where they come from, they are clueless.