Hi Beags.
Your Oxford story could well be based on fact. One well known fault of the "Ox box's" door was that pulling the wires to the "Open" pins was right next to the wires to the "Jettison" pins. Many sorties ended during crew exit with the door falling off onto the ground. Thus falling out of the aeroplane after pulling the wrong selection would seem to be a distinct possibility.
Not the first - or the last aeroplane , to have an unfortunate close location of devices that were easily confused, leading to embarrassing mis-selections.......