I imagine a few broken bones, if not from the impact of the dense burst of air, from when you'd hit the ground or anything else behind you. This is nothing more than an overgrown air cannon (the kind used at lots of haunts), this guy is crazy!!!
Your post reminded me of another 'shockwave cannon'. If you ever need a little mahem, check out srl. I was at one of their shows in L.A. several years ago - absolute anarchy. Hovercraft propelled by 130dB pulse jets, diesel flame balls bigger than a bedroom, 2x4's 'pitched' at 200mph... shows last until the fire department shows up... it was fun Here's the 'show' I was at.
Anyway, they had a shockwave cannon powered by oxy/acetylene mix. I was told it felt like a rug burn all over your body when you got hit with it... and it was meant to hit audience members