[aerohead]

Regardless of what caused the yaw,there was no weather-vane built into the car.Once you're sideways,any number of things can happen.
A more seasoned driver might have instinctively gone for the parachute at the first awareness of yaw initiation to keep the back of the car behind the car.
Perhaps the SCTA will consider allowing tail fins for cars attempting certain velocities.
Jaray and Kamm both advocated fins for low-drag race cars.