Generator back feed is a major risk to lineman during power outages. A transformer works either way it doesn't care if you put 120 in to get 12,000 or 12,000 to get 120. We always install heavy ground cables to our system before working on them. Never know when someone is going to get home from the store with their new generator and try and kill ya. We might not see ya but our grounds will destroy your new purchase. Lol

Got lucky several years ago in an ice storm. A tree had taken down a service from both the house and pole. We were putting the service back on the house and co worker said he keep getting shocked even though no hot wires were energized or even hooked up. This was in a dump of a yard with trash everywhere we finally found and extension cord buried in trash going from the neighbors basement window going to his basement window. He hooked up his furnace to the cord backwards without removing the wire to the panel and had energized the bare neutral wire trying to kill us.

Mike