Makes you wonder why trains even have an emergency brake. A button to alert people to an emergency, sure, but when does stopping a moving train in a tunnel or the middle of nowhere fix a problem with passengers?
If I designed a massive, fast-moving, unmaneuverable tube holding dozens of human lives, I think affording it a relatively safe way to arrest that momentum would be essential.
This guy appears to be using the break in the driver cabs (the unused one meant for when the train is moving in the opposite direction), so unless we got rid of those too it wouldn't matter.