If I was this guy I would walk around with a helmet on for the rest of my life, because he just cheated certain death.
After watching the video a few times, it appears to be his own fault. He’s going way too fast and smashes into the bike in front of him, sending him into the path of an oncoming lorry.
How he avoided being sucked under it, I do not know. But he was just inches from becoming a road marking and he might want to think twice about being a reckless bastard in future.