I read that the terrorists took classified information regarding allies/safe houses/etc. from the place where Stevens was murdered.... CNN probably got the journal from the terrorists.
It would seem they had to of, or we were being lied to earlier.
At least by Sept 13th it was being reported that sensitive papers/files (containing names and some oil contracts) were missing from the consulate. CNN is reporting that they ‘found’ the journal 4 days after the attack. As of Sept 16, the FBI still wasn’t in Libya, per the Libyan president.