Who is that good looking guy in the first vid?
In the second one, I looked at the orientation of the rotor disk to the machine, to see if the rotors were hinging/flapping, where the dissymmetry of lift has the lowest rotor riding on the stop and causing the stick to stir..... The rotors were exactly where they should have been for flight, there was no flap or stalling imo, the pilot simply pulled the nose up and left it up.... there was nowhere else for the rotor path to go other than where it went.... to the ground..... that was simply pilot error or untrained pilot.... or training pilot who had a brain fart. The rotors appeared to be a bit slow, but had he allowed the machine to stay level by letting the nose down, (it should never been allowed to get that high in the first place) that wouldn't have happened. That is why I think hops are a good thing, not intending to fly high, simply take off from 3 wheels, scoot along at a few feet then land on the mains and stop.... then repeat a 1000 times
It is also the reason I don't like balancing on the mains as a training thing.... but that is another story.... 
That guy was like, trying to balance on the tail....
which wont work.... as he found out 
