For my own opinion, outside of just the article - Sure, the contents of that conversation are uncorroborated, but I don't think it's fair to the author to deny

For my own opinion, outside of just the article - Sure, the contents of that conversation are uncorroborated, but I don't think it's fair to the author to deny his experience on that basis. Denying that is, implicitly, accusing him of either being dishonest, or at the very least exaggerating and misinterpreting the event. And, to do so is hypocritical for a supposedly liberal person - recognizing and acknowledging the individual experience before demanding systemic evidence in one case, but not this case. (Not that you, necessarily hold that as a valid method of understanding the world, but many people supposedly do - it's the basis of a lot of popular identity politics) You might want to actually read the article in detail - the majority of it concerns widespread bias in academic social science, and provides what's arguably concrete evidence of that. His personal anecdote is just a reinforcement of his main point, not the entirety of the article. We don't know what happened during one particular phone call, but we do know what questions (and what results were drawn) on several social science surveys.