My favourite one is where the person you know who drinks at least 4 beers a day and smokes weed round the clock seems overly fixated on the protein issue. Even putting aside the actual facts. (You can absolutely get enough protein from a vegan diet; there are professional bodybuilders who are vegan.) This person fundamentally doesnt care about health issues. They care about justifying their burger and their unwillingness to examine their engagement with evil.