OK, I see your points with the sketch and your comment above.
Yes, if the metal water line is cut, the return path is broken, if the utility neutral is 'lost'.
There have been lost utility neutrals, both OH & UG, that sometimes create havoc, and sometimes go unnoticed for some time, all dependent on the earth ground system integrity.
We collectively have to accept that the 'water piping' as an earth ground is becoming a thing of the past with the proliferation of non-metallic water supply piping. IMHO, that is one of the main reasons to install the Ufer system.
I have had a few calls over the years of techs from the water utility getting 'shocks' when changing out water meters. The utility held a safety meeting, and requires their meter techs to look for the NEC required jumper first, and if one is not present advise the owner.
They also have 'temp jumpers' for safety. Yes, we still have 'aged' homes that lack the jumpers on the water meters, and the water heater units.
