There is simply so much we do not know about this…

Just because the vulnerability was reported to Mozilla on Day X does not mean that was the day the FBI or whoever first became aware of it. They could have been exploiting it for months in the wild and only after it had been identified by a third party and patched that they finally arrested the guy because the utility of that exploit had become less valuable to them.

There is also an on-going debate as to whether this was really a child porn hit or whether the child porn was just a cover for the take down of Tormail, which apparently has been quite popular with critics of the US Government.

One thing for sure is that Tor’s reputation is badly damaged. Because if the USA can do this to Tor there is nothing stopping the security services of any of the other nations from doing it too. It’s not as if zero day exploits are cost prohibitive to purchase on the open market when governments interests are at stake.