Good points about reaction time. And remember, we're talking subway here (even though it's on the surface at that point on the line) not commuter train on a main line railroad. Things are a bit crowded and active visually, driver's peering through a fairly small porthole on the world, and if the computer is driving the train (as seems to have been the case) and is cruising or accelerating it can also take a bit of time to understand what's happening and generate an "Oh S..." reaction.