It's such a stupid argument because even if you want to (I don't) say that's true, it's irrelevant, producers/pros still have a duty of care to assess the limitations of the contestants, if they can't even do something so basic as identify someone with no ankles hasn't the stability to do a high impact landing on his feet, you shouldn't be in the bleeping job. It's insanely unprofessional. And even worse, if you do indeed know (which again, I insist they did because they didn't get him to practice a single time in advance because they knew he shouldn't be doing it) and go ahead with it anyway, you are not only stupid you are actively harmful and should be done for negligence.