This video really is very mysterious.. Saw the front wheel of the cubchai fly off, thats about it. Could't see any other debris. And smokes at the big bikes after he hit the mat rempit, indicates that something might be in between the tires (probably under the seat & stuck at the swingarm) as smokes like that may come from the excessive rubber friction of the rear tire. I hope that it is not the guy though I fear the worst it might be.

Seen a few frames after the crash something flipping at the side box, i think its the fairing of the cubchai.

Sidebox is designed not to brake (easily) and absorb impact, doesn't mean it is unbreakable though. I knew coz i have those and was hit once by a car. And was lucky i did not fell off, but about to fell off jugak (for an obvious reason). My sidebox eventually survived the impact.