I wouldn't surprise me one bit if his collar bone was broken. They guys at work really get a "kick" out of watching this video. They laugh every time they watch it.

The T-Rex is about 90+% of a 50 BMG. But the differance is that the 50 is fired from a gun weighing 30+ pounds. This gun weighed only 13.5 pounds. Less than half.

If my figures are close to being correct a 50 BMG firing a 750 grain bullet at 2800 fps out of a 30 pound rifle will have about 120 foot pounds of free recoiling energy at about 17 fps. A tyranosaur firing a 750 grain bullet at 2600 fps out of a 13.5 pound rifle will have 194 foot pounds of free recoil energy at 30 fps. Of course both of these guns will have brakes installed but you can see just how much the tyranosayur will kick.

It has been reported of people firing rifles chambered in 50BMG with out brakes installed and detaching the retinas in their eyes and breaking shoulders.