I think that is what it does. At least in this video it looks like the branch stopping the prop, only stopped the one prop and the others carried on. Although I didn't think it would spin as much as it does (kinda like a helicopter with the tail rotor damaged).What's with the uncontrollable spin?
My experience has been when a motor does go bad, it shorts out or bearings freeze.
I wonder if the H can shut voltage down to that motor with out it bringing the whole electrical system down.