This interview lasted over an hour. If he was answering wrong they should have said something.

> In this case the interviewer asked these questions to get to know the candidate in a professional setting, so they expected a diplomatic or professional answer

And there is no bias in this assumption whatsoever?

No. Reread the post. This interview was specifically explained as a non-technical, cultural-fit talk, and the interviewer "gave an impression of this being a safe space". That means they said something specific to hint that this is the case.

Don't blame the poor guy who was subjected to this. You're projecting your understanding of what is normal for the interviewer and assuming that the particular interviewer didn't cross any of the lines you wouldn't. Unless you are the interviewer or know their side of the story, there is literally nothing in the post that would suggest your reading is correct.

A simpler explanation: the interviewer was an amateur psychologist with little experience in either interviewing or therapy. They asked "interesting questions," then were overwhelmed by answers they hadn't expected and couldn't gracefully handle. That's it. Please, unless you know more about that particular instance, don't reflexively blame the candidate for what looks like a series of errors on the interviewer's part.