well looking at the picture they give, the train may have been coming around a curve so you couldnt see it until its right on top of you.
also, i dont know if this is just a thing in subway tunnels, but you really cant hear a train if its coming around a curve. its almost dead silent.
another thing is they may have frozen up. right now its easy to say that you would have jumped out of the way, but when a freight train turns a corner coming right at you, you tend to panic. the adrenaline dump will either force you to react quickly and jump out of the way or will just almost paralize you. depends on the person.