Why didn’t they keep interrogating him while he was medicated?
Because the accusations against the US military regarding GITMO were fresh in their minds, and they wanted to protect their own PC fannies, “Let those crazy allegations be said about Gitmo marines...WE are smarter than that, WE know the routine, and WE’ll be damned if we’ll let that happen to US...!”
So in short, the FBI cared more about their own reputations than they did about actual US security.
They act as if they think the terrorists will only go after Republican-populated targets. Even if they were to get such a promise from the terrorists themselves, it would be crazy to trust the terrorists to abide by their promise.
Eric Holder is worse than Janet Reno. She was corrupt and partisan, but more oblivious to the dangers to the security of the US than consciously trying to put us in jeopardy.