Mmm, I'm still not convinced! By removing the immo from the ecu yes the car runs but it has not proved where the fault was. By swapping the two ecus over, the fault is still not isolated.
If the downer car was communicating on k line and the faulty vehicle communicates on can, all that was proved was that the k line circuit is still in the loom of the faulty car!
I still suspect the issue was immo signal corrupt from the bis to the ecu.
The can trace you posted looks like a can signal but does not look correct to me, although a longer trace was needed to be sure. Can is usually in parcels not a continual trace like that.
To late now I guess to prove. Did you write on the invoice that the immobiliser has been removed and the owner should inform his insurance or you will be liable if car gets stolen!
Sparki