I would agree that the system was destined for failure, he was lucky not to have had a total failure sooner. You have to anticipate an eventual power outage when building the tank. It just so happened that the first time his power went out was not accidental, but a planned outage. Where I live we don't receive notices for that, but if they do where he live then I somewhat see the issue. I am stating that by offering anything they are atleast admitting partial fault.
It's been real AA.