This ones not so much a myth,more of a curiosity. Would a human survive a great fall in one of them inflatable human sized hamster ball orb things that people run down mountains in? And when i say a great height i mean from an aeroplane or helicopter. The team could put buster and a G meter in one then drop it from various heights onto various surfaces like tarmac,grass,a hillside,a straw field and maybe even the sea. What d'ya think?

probably not.
i doubt the plastic could withstand the pressure of impact

Sorry, even if the ball was flexible enough to absorb the impact the body inside would still feel the effects of the inertial changes. That is to say the hard part of the body, ie the skeleton, would stop rapidly (probably rapidly enough to break bones) but the soft parts would continue moving within the bodies restricted frame. this means that internal organs would be severely stressed (if not moved fatally). Even more devestatingly one particular 'soft' part of the body would squash itself down into its hard container, this being the brain inside the skull (causing massive internal bleeding and structural damage to the brain). for an example of what this might look like try putting a jelly inside an unbreakable container which is slightly larger inside than the jelly, then seal the container and drop it from a 20 feet or so. You'd still have a mess even if it was dropped onto a mattress, and that's only 20 feet.