It's hard to see what happened exactly because that video is so grainy. I could only guess maybe his rear spoiler was set too high, making the front end a little lighter. Maybe the car in front of him caused some turbulance, a little air got under the front lip, and just like an airplane wing, the low pressure zone created on top of it caused it to fly up into the air. I didn't see any serious cornering going on, and the incline wasn't that sharp, so I'm stumped.
I know it hurt, that much I can assure you.