From the looks of it, the initial impact was the one that probably got him. I can bet he wasn't wearing his seat belt (even though it wouldn't matter at those speeds).
The cabin isn't fine, in actuality, because the A pillar's been bent. When the car flipped, that's where their heads would have hit. And it looks like the car flipped onto the windscreen, not the sides There's no damage anywhere beyond the A pillar, so it couldn't have rolled on its sides.
I wonder how Abdul Jabbar is...
All through this ordeal, we haven't really considered how he is, and what sort of burden he has on his shoulders.