I think that the owner ought to pay this IF indeed he used the excess power AND IF the utility company can produce some sort of proof that he actually used that much more power. I always think you should pay for what you use. But here, did they know when the meter broke? If it's a clear case of the meter having been installed with the wrong setting, so it logged 2 KWH when it should have logged 3 KWH, then fine. But if it went defective some time during the last three years, and this was the utility's best guess, I'd negotiate something else with them, as they probably took the point of view that benefitted them the most... So in principle, I'm not against him having to pay, but I think he needs to check to make sure that the revision is indeed accurate.
You need to be at the State Department.