Did you happen to check to see if the primary protector fuses in the outside telephone interface were blown or if the CATV ground block shows any sign of damaged?
Just wondering if maybe the primary power line that broke could have fallen onto the grounded bare messenger for the telephone or CATV overhead lines and caused a momentary high voltage fault between the remaining side of the transformer secondary that was still energized and the grounded neutral and/or main bonding jumper and grounding conductors.
The messenger spans are normally connected to ground at various points along the way, but maybe the initial surge was enough to cause some issues.
That’s my attempt at playing Sherlock Holmes anyway.
I guess this would only be relevent if there were two primary OH lines and a neutral on the pole crossarms.
