So then, as he had it, the bond of the service to the ground grid was through the frame bond (strap/screw/lug etc.) and then again through the EGC via the main panel ground bus lug?
I can't blame you for firing him, if he thought he had a better idea he should have put it past you, etc..... all kinds of wrong on many levels on his part, one of which I would bet was his attitude (I am guessing because you sound pretty peeved, and an arrogant jerk can really set off fuses).
But (and my intelligence is the only one intended to be insulted here) would the service, although improperly grounded, still have had adequate ground potential? I know I am missing something. Was the lightning path too high of impedance? Was lightning and gradient voltage being routed through the main panel?
This might get into lightning protection, which as far as I'm concerned is a different cousin of the field than the one I'm in.
