I have no idea where the chase started, but knowing Stockwell station it is the last place I would have run into. I would have run into the very busy road outside it, or one of the numerous shops next to it, or into the huge pub opposite it, or up to the manned ticket box that he ran past to vault the barrier, No I wouldn't have run into a tube, vaulted a barrier and boarded a train.

I think it was a tragic error of judgment from all concerned.