Nonsense. BY the time this took place, the 71 was not a secret. Lots of still classified stuff about it, but LBJ told the world about it, and our enemies certainly knew it’s altitude and speed capabilities. Having a ground speed check from ATC was not letting the cat out of the bag.
it’s nonsense that you think it’s nonsense. it was completely unnecessary, it served ZERO national security purposes, and the only thing it accomplished was to give a pilot a chubby.
we don’t spend hundreds of billions of dollars on defense annually just to give pilots happy pants. period. end of chapter.