I was thinking the same thing.There is no way a human stopped those blades with his back and did that kind of damage. At least not without serious injury, or death.
Are you kidding???Is that blade really toast if the leading edge is straight? There would be minimal lift from that area of the blade because it is so close to the hub.
For example: I was building an electric bb gun using two RC racing motors, basically it worked like the ball thrower at them batting cages. I had two motors spinning at 50k rpm and fitted to the shaft was a 2" aluminum disk containing a 1/4" thick rubber seal. This seal was so tight that it took two of us to stretch it on; it was also bonded with special rubber glue. well as we proceeded to power up the motor I could not believe my eyes this seal broke loose from the glue joint and turned itself into a 4" fly rubber ring, that’s right the rubber seal grew nearly twice its size and came off the disk......well back to the drawing board. If it had worked I would have been able to sling bbs at nearly 500fps using all electric.