That happened last Sunday on the Supersport Race at Monza, what you failed to see because of the fast moving pace camera is that he went outside the rumble strips, caught some dirt and highsided horribly, hence, no fence on that side... I'm guessing, it will be some fence for next year's race!
Pay particular attention to the way the back of his head smacks the pavement when he comes down from on high.
There's no way you could brace yourself from the impact with the ground in that situation. The back of his head would have looked like a pumpkin on November 1st if not for that helmet. I for one am (and have been) a believer!