Depending on how fast and high the plane is flying, I'm surprised a deployment like that doesn't rip the chute or crack ribs. Any airborne vets care to comment?
A parachute isn't gonna rip like that. In fact, that kind of deployment is how some types of equipment are dropped. A drag chute is deployed, which pulls equipment out of the plane and lands it. Here's a video demonstrating that: https://www.youtube.com/watch?v=1RXoG-GeGek As far as the harness...it's a full body harness, strapping around the torso as a whole. I would only assume that because he wasn't ready for it he could've had muscle strain coming down, but I can't really attest to that.
Usually when equipment or people drop out of a plane, the plane slows down or is flying lower. Not doing that is what i figure would cause those problems.