Even a Navy pilot has no actual basis or experience on which they can justify a claim to "visually identify" a 100+g acceleration. The downwash, sure (though it's just as likely they simply didn't see it, it was obscured, or had the craft been a few inches lower you'd see it).
Except they are probably the best people to at least take a guess of the distances covered in air and the amount of G's such maneuvers would be subject to, since they're the ones flying around at high speeds, covering great distances and dealing with high G's.
Plus, isn't that part of what the whole dog-fighting thing?
