The author shares their experience riding on a Class 800 train in the UK, which is a replacement for the older HST trains. They discuss the design of the disabled toilets on these modern trains, noting that the older models had confusing door controls that often led to people being unable to lock the door correctly. The newer designs feature a lever that is more intuitively comprehensible, but it is actually just an input to a microcontroller. The author then explains a vulnerability they discovered where the door can be locked incorrectly, allowing someone to jump out before it closes. They provide a video demonstration of this issue. The author mentions that this is not the first vulnerability they’ve found on a train.
https://www.devever.net/~hl/traintoilet