I was thinking the same thing aussie.
I thought about Capn bloggs answer, so slowed the video down a little. Seems to me, tho you can't see the cable, that the rotor has taken the cable around the fuse and garroted the tail boom The boom is clearly the first item to actually show any sign of impact related movement.
Be interesting to see the results of that part of the investigation, Because if bloggs is right and the boom simply failed, you'd be a very worried AS350 driver if that was the case.
Interesting the comments in rotorheads about the wearing of bone domes. Not so sure I'll giggle at any pilot wearing one again.
At least everyone is safe on this one.