Ooooo, that was painful to watch. That poor old left side guard rail looks to have seen it's share of contact. I witnessed a similar incident involving a red '99 GT about three years ago, although not quite as bad. The driver was a middle aged guy and it was his first day at the track. His wife had warned him not to go that something bad could happen. Of course, he assured her it wouldn't. I went down to talk to him after and the poor bastard was scared shitless to go home.
I remember seeing a lot about that crash. What happened was he popped a head gasket, which pressurized the block and popped a freeze plug, dumping water under his tires, that's what made the back come around. Not a whole lot you can do in situations like those.