a motogp bike wont break your bones if it just falls on you, maybe if it lands on you though from say a highside.
the pass rossi did was a bit ambitious but it was just a racing incident. if the front end held it would have been one of the highlights of the race, as he was leaving stoner behind in lap times.
that exact passing/crash happened to me a few weeks ago when i was racing. i was alot stronger under brakes than another rider so passed him in the braking area going towards the inside of the track. got past him and then the front end let go, sending me sliding off the track. as i was sliding off the track, the rider i just passed ran into my back wheel, sending him flying off the track into the dirt.
i was still a fair way back from the guy when i started my move, but i would pull 4 or so bikelengths under brakes, so it was easy.
i had no marks from the accident but he got a busted collarbone. i feel bad but it was just a racing incident. the worst part was that i am mates with the guy who ran into me.
but it was funny seeing the same sort of crash in motogp straight after my crash.