To be fair the FBI did do a timing correlation attack to confirm his identity (linking the traffic they saw leave him to the traffic they saw arriving in the IRC room). But they already were pretty damn sure it was him before they managed to target him with that attack. What I take away from this is that the FBI knows how to do timing attacks, and that they didn't own any of the entry guards any of these hackers used for the entire length of their investigation (or else they would have done timing attack to locate them instead of to confirm them after they already were pretty sure they located them via other means). Of course this assumes the media stories can be trusted, if the FBI did timing attack to locate any of them they would never let it slip, instead they would say what they are saying right now: other things happened, like Sabu forgetting to use Tor once.