I thought the hearing was behind closed doors and the testimony was classified. Anyway Brietbart doesn't offer an explanation how he got the supposed Petraeus quote. And the only named source I've seen who has claimed Petraeus has said this, is some Rat congressman from Maryland who attended the closed door hearing.
Somebody is trying to rehabilitate Petraeus, and Gingrich is being used to that end.
I can't come to that conclusion and I think it's most likely wrong.
Gingrich has the same source problem you correctly identify with Breitbart - no names. But Gingrinch's contention seems rehabilitative, to me, to Petraeus. At least I think conventional wisdom is that it's better to not be known as promoting or initiating the "movie made 'em do it" theory of the attack. Perhaps your opinion differs.