There's no telling what all he's done, but I'd be willing to make a safe guess that the block and internals were all stock.
He's got a nitrous kit on the car, so if he was running a REALLY heavy shot or didn't set things up right (correct plugs, etc.), that would definitely help in explaining why things went BOOM.
With all the plumbing under the hood, good luck getting the dealer or the insurance company to pay up...
