On the one hand it's great that your friend has bothered to look into Tradition, and familiarize himself with the most punctuated traditions of Western Catholicism, i.e., the teachings and canons of the Council of Trent. He may be running into something of a culture curve, though, as in the west we make a far bigger deal of authority than they do in the east (whether the Catholic east or schismatic east). While reading the texts of a council can be edifying and instructive, a private Catholic's understanding of what they mean is just that: private, prone to error.