Based on what you've said - I think you're screwed. Glad you're here to tell the story though, because your survival is the really important part!
I'd still discuss it with a good lawyer, but I think your best hope is that they throw a few $$$ your way to preclude a legal battle. After all, 2/3 of something is better than nothing.
And for what it's worth, I hope you can post back in a few weeks and tell me I'm full of crap because the other guy's insurance paid everything in full.
