No, that's not my point. Cuba is a much more restrictive country than the US. Even if the prisoners were to escape, where would they go? It's an island, albeit a large one, and not as easy to escape from as, say, crossing into Mexico, where they could establish contact with other terrorist groups. Plus, Cuba's security forces are much more intrusive and its society much more exclusive, making it more difficult for strangers to hide.
I'm not dissing the USA, by any means. It's just that, because of the freedoms we have here, it's easier for a criminal, once he's escaped, to disappear in plain sight.