I have never heard of this and it sounds insane. You wouldn’t kill everyone or no one, you’d probably kill everyone and the people on the train too. When I look up purposeful derailment the only incident I find is that crazy guy who crashed two trains into each other for fun killing some spectators.

Edit: hey more googling. You could argue it happened once and calling it a "trolley problem " is generous. The incident I’m finding was a runaway train in Australia. A runaway train is a lot different and usually they don’t try to fix them like that, but by applying the brakes. It’s also worth mentioning it was a “controlled” derailment and not just some guy flipping on Deja Vu as he sees if he can emulate initial D. There was no one in the area. Also in general I feel the trolley analogy has long fallen apart at this point.