If there is a short to ground and the current finds a return outside of the cable the problem appears.
That is the scenario that I described.
With an EGC and other parallel paths available through conductive structures the EGC is still the lowest impedance path.
(That it is the lowest impedance path is untrue if you read the problem as I wrote it.)
Okay, I will explain the point for you and anyone else.
A lot of current will return on the conduit.
That means that the magnetic fields around the 237 loops will not be cancelled. They will act as chokes limiting the fault current.
Whether it is significant or not requires some calculation and kowledge of whether the imbalance will act as an inductor to reduce the impedance on the EGC. That's why I am hoping that Scott will answer.
