> I think this is not as interesting a philosophical problem as he is making it out to be. If you are standing next to the brake and someone says 'hit the brake his arm is stuck', then you hit the brake.

If it's expected/uninteresting for someone to hit the brake when someone shouts at them to do so, then is it not interesting to consider why the opposite happened in this case? ("I pointed to the person next to it and shouted [...] They didn't, so I ran down the train")

> You don't work out some complicated moral calculus.

Which I think is think is one of the author's points, that "morality problems often suggest a frame of mind where we have time to fully reason out the likely effects of each of our options" and that doesn't match reality.