I think a spy for al Qaeda. The info about exact layout of the camp might be for a few reasons:

1) Rescue Low-probablility scenario. Lots of angry Marines with guns. Castro's police state likely would not tolerate such foppery. (Although I do recall something about members of GIA cells in Canada taking Cuban vacations in late 2001 - early 2002, right after Camp X-ray was established.

2)Break-out. Certian high-risk al Qaeda members might be briefed on camp layout for worst-case planning. Or, better yet, al Qaeda might intentionally give up several people - say some sort of careless use of a sat phone.

The hope is that the one or more of the "careless" al Qaeda operatives will end up in Gitmo. These men would be briefed extensively on Gitmo - security weaknesses and who is where.

3)Assassination. Same scenario as above, with a twist: "When you get to Gitmo, Kill 'X' at this location and 'Y' at this location. 'X' knows too much and 'Y' is a cooperating. This message will self-destruct in ten seconds."

4)All of the above. Debka (I know, I know) has published some interesting information regarding al Qaeda's East Africa operations. Here and here.

Let's suppose that these reports are correct. If al Qaeda can operate like this in East Africa, might they be capable of such a thing in the Caribbean? I think al Qaeda has Caribbean operations. Possibly supported in part by Castro's buddy Hugo Chavez.

The US might be on to them. The DC sniper attacks exposed part of thier operations when John Allan Mohammed was caught. Mohammed was apparently a frequent flyer to Carribean locales - while he was living in a homeless shelter in WA. But, knowing the way things work in the FBI and CIA, the connection hasn't been made. Perhaps by individual analysts - but the middle management will have to be forced, again, to investigate this stuff by the upper levels of the administration.

Oh, man, sorry about this long aside. Anyway, imagine a sea/air attack at the same time specially planted sleepers inside the prison take action. Perhaps a few could get out in the confusion. Yeah, it's a military base - a hard target. But are the sentries ready? I suppose the imam would have some insights on that, too.

In addition to these scenarios, I can imagine that the physical layout of the camp and the locations of the prisoners might yield some clues. How does the camp operate? Who is regarded as an important prisoner? Are the Americans underrating some prisoners and overrating others?

The names of those being held are important, too. The enemy might not know, exactly, who is held. Which cells have been compromised? Which safehouses? Which money conduits?

This guy might have been recruited as a spy for a state. But just about the only things they would want to know are: who and how many? They wouldn't particularly care where. That's what makes me think al Qaeda.