As someone who makes sure they never leave early, even if I'm getting a tip from P staff. I've been accused by some passengers of leaving early. What this normally means in a train timed to depart at eg 14.30, is leaving at 14.30. They look at the PIS and see a train timed at 14.30, the time on the clock says 14.30, but the train is starting to move. They have arrived at 14.30, and been unable to catch the train. I'm thus called a fu#@ing bi%£h for leaving early.
If I'm running correclty and have the time, for that departure at 14.30, my routine is:
14.29.30. Blow whistle.
14.29.35. If platform and doors clear, close doors
14.29.40-45 Once doors closed and bill lights out, check again and close local door
14.29.50-55 Signal driver.
14.30 train starts to move (hopefully).
If anyone arrives after the 14.29.40 sequence, there is a chance they are not going to catch that train. For us, to reopen the doors involves.
Calling up the driver and asking for the doors to be reopend. This can add up to 1 min plus delay I'm not going to do that unless I really have to, as this will delay the train. Thus effecting all the passengers who did arrive on time. On some occasions I might hold my local door open a bit longer for a 'runner'. But if they fail to respond to me shouting 'here' and stand at another closed door, then , sorry, but no. (and you would be amazed how many folks do this). And I'm gone.
Of course, by assaulting the guard, the original passenger, A missed that train, and B will be missing many more trains in the future. And with any luck, will be soon missing feeling safe in the shower.