Serious question: once the train had come to a stand short of the correct stopping position (for whatever reason) and the doors had been opened, what is the correct procedure according to the rule book? Should the train have essentially been dispatched by the guard/platform staff in order for it to draw forward safely?
If you have a guard then you need to communicate with them to ensure the doors are not released if the train is not in the correct stopping point and so the passengers can be informed. If however the doors have been released either DOO or by the guard then the rule book is clear on a few important details.
Before you move the train anywhere, even to the correct stopping point a thorough check must be made to ensure no one has fallen from or exited the train. This can be done by either driver or guard if the train has one.
If you or the guard are not sure or if someone has then you must inform the signaller/driver immediately and consider the actions required to keep that person safe.
The doors absolutely MUST be closed again and the train checked before any movement takes place to get the train to the correct stopping point, the last thing I'd do is continue to detrain at an incorrect point, even if using egressed doors only, secure the train and position it correctly before taking further action, this incident will need reporting so the likelihood of continuing in service is low anyway.
You also have to be 100% that no one is in danger if you move the train. If you move a train that has stopped short and released and you hurt someone you can expect your day in court to end badly.
Stop shorts are nasty incidents that can go even more wrong very quickly, I've seen CCTV of stop short incidents at my TOC and in every one the passengers wishing to alight from non platformed coaches have noticed what has happened but still decided to attempt to alight anyway and have been injured badly in the process, in one case an elderly lady and her daughter made the jump from an EMU leading to the elderly lady breaking both hips. In the same incident a passenger pulled the PASSCOM and then followed them out the doors onto the tracks, no one thought it safer or worthwhile waiting. It can be a trap for train crews to think 'they'll see and stay on the train' but experience tells me this isn't the case.