Having seen the clip several times it seems that
1. the rope breaks about halfway down the line and if you look closely you can seen just before the breakage there is some sort of knot in the rope this proved to be a breaking point to start things off
2. just backtracking a bit before the breakage the 206 had a huge nose down attitude in trying to pull this boat and if you look at the boat its certainly mooving quite rapidly before the breakage occurs
3. you could imagine the rotor thrust at this huge nose down attitude and basically when the load or sling broke he just catapulted into the water. he would just not have the time to pull out of this unusual attitude.
4. I could imagine the insurance company would be a little less than impressed!!
Just my opinion thats all