The U2 was being threatend by mig 21s zoom climbing a looooong time ago, they just couldnt get a lock on as they were basicly on a ballistic trajectory at that point.
All this time later, a f16 getting within missile range is no surprise to me.
Not that I wholly believe the video portrays that
I have always had a soft spot for the U2, but its days of invulnarability from fighters were over 30 years ago