frankly, unless I'm missing something rather obvious, I'd suggest that
opening the wrong set of doors on a tube train is almost impossible for
a normal person to do - otherwise it'd have happened more often than
once.



It has happened several times in the past. I don't have any facts/figures
about it, but I remember reading a news report about the same thing
happening on a circle line train at Kings Cross a few years ago.

Also many years ago apparently a Central line train on the Woodford -
Hainault shuttle service went from one station to the next with the doors
open, the driver forgot to close them and at the time there was no
interlocking device to stop the train driving away with the doors open.

Andrew