I know you want to keep things clean but sometimes it takes a bit to respond to things for multiple reasons. Simply closing a topic without giving the creator an opportunity to re-open it is no bueno.
It would be good to at least allow the creator of the incident to make a comment to re-open the thread to further the story. But not closing stories out would be ideal, forums are supposed to be in place for people to communicate and what if someone has the same question as one that is already asked but needs more discourse? We have to start a new thread and start all over again instead of continuing the existing thread.