You are correct about that. That is why the person "in back" is almost always to blame - they must maintain control of their vehicle. And if Sparky gets his jollys running over poor little rice-mobiles, he will find out sooner than later I think.
I see the same thing all the time with insurance coverages. If the pay-out from their auto policy doesn't cover the judgment amount, here come the liens, garnishments, etc.
(Pushing your leg? Was it as good for you as it was for me?)