What do you mean by “boots on the ground”, do you mean our Special Forces that were there killing those 100-200 mystery men?
US soldiers landed at Son Tay and checked the prison cells where US and ARVN LOWs had been held but were moved out a few weeks before.
However our planes/rescue choppers killed many remaining NVA soldiers and a few Russian advisors (possibly interrogators or intelligence agents attached to them). There was at least one book or study/report published on the raid and one kept secret.
A number of my friends and acquaintances were POWS at the Hanoi Hilton and satellite camps in or near Hanoi itself - Jeremiah Denton, Bud Day, Mike Be getting, Larry Stark, Paul Galanti, Randle, etc. Throw in Nick Rowe (Five Years to Freedom) re POWs in SVN, for good measure.
There are many stories about the war that are still classified including something I helped uncover as well as one historical footnote incident I got from an NVA senior military officer senior defector.
Life is indeed strange.