Cameron travelled with the McCain team. He was on the plane. He got Stockholm Syndrome and was used by some as a willing mouthpiece for their smears.
Major Garrett seemed to suffer from the same problem traveling with the Obama team. He smiled the whole time he spoke about how upbeat and positive and confident everyone was on the BO campaign.
I think both got to think of themselves as somehow being campaign insiders and abandoned journalistic skepticism as a result.