Just from looking at the picture, I can't imagine the car was at a complete stop in the middle of the road. Hitting a stopped car at 100+ MPH you'd see far more damage and I would think the car would have flown high up into the air and/or flipped several times. I've seen other wrecks involving very high speeds and every one of them resulted in far more catastrophic damage.
It seems to me the car might have been moving when it was hit and the Vette clearly was slowing down as Ruggs probably started to get into the brakes before he hit the car. I'm curious if there were skid marks that would indicate how much he braked before the collision.
All that said, I'm not sure there's anything that would keep Ruggs from serving significant jail time.