You're reading about an accident, and then assuming the amount of risk involved without knowing anything about the sport. Accidents happen all the time, in all sorts of ways. It's very possible to do something like this and have a large safety margin, as has been shown by his 24yr history of doing it. Someone who is this experienced at what they do, in a dangerous seeming sport, will be very well aware of possible mistakes, and how to mitigate them. I personally think teaching your child to be "safe" and not take "risks" is kind of stupid. I'd much rather teach my child to learn how to push the limits intelligently, and see what in this world is possible.