Over the past couple of weeks, I have seen two trains stopping abruptly on approach to North Greenwich in the evening peak - presumably because people are leaning on the doors as the train slows down. The trains are often quite packed, especially when there are minor delays.
After a short period, the train is restarted and slowly pulls in - on these occasions, it was only the second half of the last carriage that wasn't in the platform.
On my evening commute home, I have seen an external yellow light come on for a couple of seconds a few times as the train pulls into North Greenwich, and yet it hasn't come to a premature halt. So then I wondered if it was actually anything to do with people leaning on the doors at all/something else/if the train only stops if the door closed indication is lost for more than a couple of seconds?
It makes more sense for the train to stop if a door closed indication is lost when a train is pulling out of the station (in case a person/object is trapped in the door and getting dragged) or when the train is travelling between stations (in case a door opened for some reason), but when the train is pulling into the station, braking, and only half a carriage from stopping correctly, it seems much less likely that there would be a need (?for the software) to apply the emergency brakes?
When a train loses its doors closed indication ("pilot light") the train stops motoring but the emergency brake is not applied; it is the driver's responsibility to do that. The external light you see is an indication that a door on that carriage is not fully closed. (I hesitate to say door open, because it would only open at most by a few cm if that and as you state this is most likely a result of someone leaning on doors, or possibly a weak interlock causing a door to momentarily open slightly under braking.) I imagine the discrepancy between scenarios you have seen is simply the driver's reaction time in applying an emergency brake (or not).
Although doors SHOULDN'T open by more than a small amount, I believe it has happened where a door has fully opened whilst a train was in motion, obviously due to some kind of technical fault, so I would always advise passengers not to lean on doors anyway! (I'm not sure whether that was a Jubilee train though.)
No-one ever fell out of the subsurface trains when they had hand operated sliding doors that were sometimes left open when between stations.
I experienced a lot of 'kangaroo hopping' Central line trains yesterday - what with the signalling issues wrecking the service and the Elizabeth line closed east of Stratford the trains were very crowded with many passengers crushed right up to the doors. I was hoping that the train driver would make an announcement about not leaning on the doors - one reason for this was because I overheard other passengers discussing this amongst themselves - they thought that the train driver was causing the train to kangaroo hop whilst leaving stations on purpose!
I did hear an announcement on a Jubilee line train from the driver kindly telling passengers not to lean on the doors “as it may bring the train to a halt”. This was on Friday at about 4pm at Green Park, probably at the time where the intervals between services were quite a bit.
With modern safety culture I think people are less cautious about possible failures and the consequences thereof. If one had previously experienced trains belting around the place with wide open doors, then there might be more respect paid towards them! The RAIB have on many occasions noted an expectation that train doors will behave similarly to lift doors and re-open automatically in the event of an obstruction, such as a hand or an umbrella being thrust between the door leaves as they close. An expectation that can sadly prove all too fatal.
No-one ever fell out of the subsurface trains when they had hand operated sliding doors that were sometimes left open when between stations.....
My experience on the Continent was that people liked to travel with the double doors open during the hot months. On the LU hand worked door trains, was there a way for the guard to check that all doors were latched closed before giving the start signal to the driver? On the Southern Region slam door trains an unlatched door handle laid out of line to all others.