I thought it was Brian Williams prompting Russert but Williams says it’s news to him. Raw Story contacted NBC and got the runaround — open mike, mysterious voice, no way to know, we’re working on it. But the secret deleted post at the NBC politics blog has since been restored, with something new to chew on. Can it be? The man on the grassy knoll is … some know-it-all wonk mumbling to himself in the audience?

*** UPDATE *** After reviewing the tapes, NBC determined that an open mic picked up a whisper from the audience. It is unclear who it is that says it, but it was not said by any of the candidates, was not heard in the hall and, more importantly, not heard by the candidates.

Romney responded so quickly I felt for sure he’d heard it and had jumped in to preempt the rest of the question. Pretty awesome that he knew where Russert was going without any further information.

Update: Hmm.

Update (Bryan): I have to say, I think this “second whisper” is insane. Yeah, there’s a whisper there but for someone to make anything nefarious out of it is a real stretch. This was a live debate. You have mics all over the place in that auditorium, including at least two that are pretty much always hot. They’re the ones attached to the moderators. Plus the four on the stage and whatever others there are add up to a lot of potential sound sources. That one or two might catch a stray whisper, probably between one or both of the moderators and someone giving them a cue or trying to get their attention for some reason, ought not surprise anyone. Apparently it does though.