QUOTE:
"There should be solid 0V between neutral and ground at the pedestal, right?"
END QUOTE
Right, should be zero to low millivolts depending on the load current in the neutral wire.
IMO, the bad pedestals probably had a bad ground, as in open and/or resistive path back to the point of supply bonding between the neutral and ground.
Second thought, could have been a high resistive neutral wire as well. If you were to take a VAC reading from the Ground to Earth at the pedestal we might then know which...........