I don't know where I would get it analyzed or what I would get it analyzed for. I doubt that I will ever know exactly what happened. As to the headspace issue, would someone please explain to me how excessive headspace would cause such a catastrophic failure. It would certainly cause case separation and gas, etc released around the bolt face but how would it contribute to such a pressure spike? It would seem to me that excessive headspace would cause less pressure in the chamber as gas is being released between the boltface and the mouth of the chamber. Or maybe not.

Here's an interesting article on the subject from the illustrious Riflechair:
http://riflechair.########.ca/2011/03/evaluating-headspace-lee-enfield-rifle.html