Well,I can understand where you're coming from,but if he had gone to the first floor and hunt the prisoners from there, the strenght of the group he'd face would be a lot bigger, going from bottom to the top he didn't allow the prisoners to free many convicts from the most dangerous levels, because they were to worried to escape from him,if he waited for them in the upper levels,he'd have to face a much bigger army,with tons of prisoners with higher bounties, chasing them from the bottom all the way to the top was a smart decision, considering he told the ships to leave the place, he just got unlucky because of jinbei,but that was one hell of an escape,nobody saw that coming..