If no signs of water could have been jumped with reversed polarity . Or somebody let the smoke out of it with a power probe . I bet you sell the shit out of those don't you pt ? That video showed what they do best .
Sigh.
I would sure as shit hope they are protected against reverse polarity.
As for Power Probes, they are nothing more than a jump lead with a meter (or fancy digital display depending upon model).
In the hands of a skilled technician, they are a fantastic tool. But, as you've apparently only experienced the skill level of Factory Trained Land Rover mechanics, I'm not surprised that you've only seen them used in a manner that caused more damage. Then again, there probably is no Land Rover service instruction indicating one should use a Power Probe and God knows, Dealer techs HAVE to follow the diagnostic tree or they won't be paid for the diagnosis.
I had a "Customer" try to diagnose a problem with an HID lighting system with a 12 volt circuit tester. I tried to tell him it wasn't the right tool but he kept telling me he knew what he was doing.
Shortly after hearing the zap, I told his brother that he might want to investigate his brother because ti appeared as though he might have shocked himself pretty badly because it looked like he was unconscious.
I refused to warranty his blowed up circuit tester because I'd just told him it was not the right tool for the job.
When I see driver transistors cooked like that, I expect to find a short circuit or other excessive load has been placed upon the output. Hence my comment about investigating further before just slapping a new ECU into the vehicle.