The courier was operating in Pakistan when he lead agents to compound. He was never in Gitmo.
Yes, but the information to find him was gained from interrogations at Gitmo. Interrogations that would have been subject to full disclosure during a regular trial. Get me now?
They would have never found Bin-Laden had they followed through with giving the detainees a fair trial, because Bin-Laden would have been tipped off just as soon as prosecutes disclosed any information they have. Which they have to do in a fair trial.