Looked like his shoe got caught up pretty good between the rearset and road, surprised he went without injury
There is injured and there's hurt. He's lucky he wasn't injured - but I'm sure he was hurt the next day.
My read - he touched down the peg or other hard part and panicked. His panic reaction was, for whatever reason, to remove his hand from the bar. As a result he wasn't able to do a couple things that would have prevented the crash
1) More throttle - controlled addition of throttle would lift the bike suspension and tend to right right the bike
2) Use bars to right the bike - He had plenty of road on his side of the the dbl yellow and was nearing the exit of the turn.
He could have saved it. bike never lost traction - you can see in the slow mo version that the bike quite happily rights itself and might well have made it he'd actually fallen off.
