Like most liberals, you are approaching the war on terror as a police action, i.e. prosecute them and put them in prison. These terrorists are in a grey area where neither prisoner of war, in the traditional sense, or criminal prosecution fully applies. Every last prisoner in Guantanamo should have been brought before military tribunals and then executed years ago.
And, no, letting 5 terrorists go free so we could save the skin of a guy who walked away and all but joined the enemy was a stupid thing to do. But I wouldn't expect you to call Obama's screw up for what it is. You've always been quick to defend your guy.
Please don't craft arguments for me when you can't produce consistent, sensible rationales to support your own flawed conclusions. Again if you brought the prisoners to trial in a military tribunal, the Constitution, in which you wrap yourself so tightly but seem not to understand, would still demand that there be formal charges, discovery and due process. This is exactly what the government did not want to happen.