HELP - truck will not start - tried everything - HELP PLEASE!!!

[HummerJim]

Saw something similar at an offroad event where the cables where crossed on the battery for a jump on an H2 and there was smoke. After that the H2 wouldn't start. At the end of the day we got him a new battery and helped him put it in, but it still wouldn't start and couldn't pull his key out with a new battery. He was also getting weird messages on his dashboard display and couldn't roll down the driver's side window.
He had it towed to the dealer and the wire that interacts from the ignition with the BCM was fried as was part of the Body Control Module. As it was expained to me by the owner later, the BCM has to interact with the PCM to start the H2. I think the tow guy owes you big bucks, but will probably never admit he screwed up! HumTech could explain it better and might know of something else.