No for safety reasons once the doors have closed they should not be reopened to anyone as the driver or the guard has the responsibility to ensure they have a right time departure to keep the train on time otherwise they will get a please explain at some point down the line ie if a train left me 2 minutes late heading into London, it could lose it's path from Alexandra Palace and end up being late arriving which would rightly **** off the passengers as they should have a reliable and punctual service.
These power operated doors are very powerful and can easily cause injury which is why I detest idiots who run though the doors when they are closing or hold them for others, the ones who hold the doors think they're doing a good deed but they wouldn't do it if they had to pay out a few hundred or thousand ever time that train got delayed because of their actions.
There are posters at stations advising when the doors will close and they advise this to be able to run a decent service for all.
Not so long ago, some passenger running for a FCC train fell down some stairs and injured themselves with a ambulance being required to deal with them, luckily it was just a few cuts and bruises but what if they broke their leg or similar injury?
No, as far as I work passengers do have the responsibility to ensure they get to the station with plenty of time to ensure they have time to buy a ticket, get a coffee etc...and get onto the platform without having to run and potentially injured themselves or others, I for one don't reopen the doors once they have closed as I have a requirement to ensure the passengers have a reliable service not only at my station but at the next calling point too, what I don't need is some passenger being abusive or throwing a tantrum just because they couldn't be bothered to get to the station with some time to spare.