If someone uses wrong evidence, just tell him the facts (specially scientific), it serves the purpose, no outrage needed.

e.g.: like someone have stated here that a pig is a clean animal, more than a chicken. stating a fact, no more.
No one argues with fact (if they are facts)

Regardless, I will still eat chicken, not pork.

"The larger grows the island of my knowledge, the
longer stretch the shores of my ignorance."
William Blake