“I don’t know how he was able to come into contact with the “third rail” because everyone I’ve seen had a cover to prevent maintenance people from accidentally coming into contact with it. The pickup shoe fits into a slot.”
That’s New York-style third rail, called “underrunning” third rail. Chicago uses overrunning third rail, where the shoe slides on top of the rail.
Decades ago there was an intercity line running west out of Chicago, that also used overrunning third rail...at grade level! (Much of the area was still prairie...and people back then still had common sense.) Anyway, my father had ridden the train out to Wheaton on business at the county courthouse. While waiting at the station for his return trip, he saw a stray dog ambling along the tracks, which suddenly stopped next to the third rail to lift a leg. Last thing that dog ever did.
I saw two types in NYC (moved away when I was twelve to Washington state) - there was that covered one and then the other type was in the center of the tracks in a slit. Those were only used in subways where water couldn’t get into it. I was told that the power was 600 volts at 400 amperes. That’s a lot of whoopie.