Might you be a threat to your interviewers?

I've heard this from more than one of those unpublished behind-closed-door candidate evals. I've heard them live during when I was an interviewer. Or since I'm intensely interested in the subject of humanly fallible hiring managers prematurely discarding capable candidates, people share these stories with me. Goes like this:

  1. Candidate does all the right things. Researches company. Targets all material.
  2. Candidate gets invited to interviews. Speaks of company products, admiration of the firm in the industry, points out his role accordingly. Asks if he's correct. Affirmed.
  3. Candidate seems to be greatest match, with corresponding personality of confidence (not arrogance.)
  4. Candidate not extended offer.

Why not?

  • Hiring manager says, "This candidate knew far more about the company than any of us. He's going to make us look bad."
  • Potential coworker invents a flaw. Doesn't want a competitor

I wonder how many times this happens, spoken or unspoken. It did happen to me once, when 3 years later I ran into an interviewer who said, "After I saw what they did to you and others like you, I wondered, how did I ever get hired there?" He was broken-hearted, he departed.

Has it happened to you? Have you witnessed it happen to another job hunter?
Details? (without names, of course!)