If he only had standard vehicle insurance, it wouldn't cover him if he were driving professionally.
He'll take the fall because Uber's going to do everything in their power to ensure the claim doesn't hit their insurance. Fortunately, the CPUC passed a law last summer to ensure that the ride-sharing companies have to actually carry a significant level of insurance for their drivers.
Fortunate in the sense that this girl's family might see some sort of consideration for their daughter's death and the other injuries.