Actually its the same. Evel Knievel figured out that if he practiced, concentrated, trained, and calculated carefully enough, there was a slender envelope of perfect safety.
Same with these guys. Perfectly safe, as long as they stayed in the envelope.
Kind of like a jet - it's wings are way too small for its weight, unless it goes really fast. Solution? Go fast. Perfectly safe, millions fly this way every day. As long as they don't slow down, they're fine.
That's why they say, envelopes ain't just a river in Egypt.
No, that was his son. Evel's medical records are enough to prove he was a daredevil. He didn't take a scientific approach, for him it was mostly "that looks about right" attitude. I admired him just the same, because he was a pioneer, an original.