Read the article. He does precisely that, he investigates his assumptions and finds that he was wrong.
I knew snopes was dubious over a decade ago because I fact checked their fact checking. I do not depend on just one source for anything. I am not a reporter just a goof-ball with a keyboard. Yet I knew things that this "academic" did not because he assumed, he never questioned until the wheels started coming off the wagon.
He gets a small pat for actually looking in the hole after someone else dug it. He gets a kick for not doing his job for years.