A case of this unrelated to DEI that I personally got into was the author of this book:
He is / was an English professor at Loyola University. I sent him a rather lengthy e-mail absolutely demolishing how amateurish and poorly researched his book was. His response to me was little more than:
I have a PhD and am a credentialed academic. The book was peer reviewed. You are nobody so STFU.
The book is easily provable dreck. It is amateurish. I characterized his bibliography as "A selection of common general references and coffee table books..."