I can see the reasoning behind the decision. Basically a spring type system to absorb shock and return energy to the legs. But as far as cybernetics? where the brain can control a synthesized appendage? I think we are nowhere near the threshold for that.

b-

The way the sporting world is going I'd let him go for it. If he wins just put an asterisk next to his name & time.

After all, he would have a "leg up" on the competition! (Ouch.... )