Don't get me wrong, I get what you're saying. My point is that Universal isn't full of idiots managing it. If they decided that a net or a roof/awning would fix the issue, don't you think they would have done it? I don't see Universal adding metal detectors or other things as a first-step solution. I also don't think the Disney argument is appropriate when it comes to this situation as RnRC doesn't enter guest areas as spacious as RRR or Hulk.
I'm also not suggesting that metal detectors are the best possible solution.
You're right, shoes can come loose. A button down shirt might too. Basketball tearaways also. Ban clothes. On second thought, what if you have a pre op transexual on board with some unattached "equipment"? Perhaps we should at least mandate boxer briefs. Boxers, which have buttons, clearly pose some degree of risk....
If anything can become a projectile, and a guest was hurt by a projectile on the ride, why would the park ever risk legal action by dueling the attraction again?