First issue: I am not sure about those "pure motives." but I do generally credit an author when he reports his own past experiences. Paul surely sought the approval of the Jerusalem community when he was negotiating his Gentile mission, since it did depart from Jewish practice and identity. Yet I don't see how anyone can get behind the text and read Peter's denial in broader terms. There are just too many silences to do more than a very skinny historical portrait, which leads me to trust the tradition of Jesus; teachings, death and resurrection, however one interpret resurrection. I am at base traditional, although I have many differences from the clerical teachings of all the churches. We can have deacons, priests, and bishops without installing a dichotomy within the church.