Agreed. He may be a lib from Oregon, but he's not stupid.
Also, although I can't put my hands on it at the moment, I have read that all licensed tour guides in Italy adhere to a code of conduct that requires objectivity and respect for everyone regardless of where they come from. Indeed, the tour guide industry in Italy is highly regulated and very competitive, and while this guide could be guilty of the rant, as described, I have my doubts since it would have put him at risk of a large fine, suspension, or license revocation.