with his left hand, he's telling his bike to stop! and with his right hand, he's fixing up the loose dirt beside the boulder. rider courtesy right there!
the leatt brace is supposed to break under a significant impact in order to route the stress away from your spine and neck to your shoulders and chest, if it broke, it saved your neck, haha
that rock below him looks ominous. hope he didn't break his back... definitely would invest in a pressure suit, neck brace, and full face if I was riding at full speed where things like this could happen...