It seem Bianchi suffered a Diffuse axonal injury, Doc may know what that is, but for more info see wiki http://en.wikipedia.org/wiki/Diffuse_axonal_injury
After reading that the outlook does not look bright for the guy.
It looks like the side of his car connected with the corner of the JCB. His head must have hit the tractor unit as the side of an F1 car is the weakest part.