That's really true. At the end of the day, you are being interviewed by people, and people are all different in the questions they ask and the answers they want

That's really true. At the end of the day, you are being interviewed by people, and people are all different in the questions they ask and the answers they want to hear. If the author made a mistake then it might be that perhaps he wasn't watching for clues that his answers were being well received. Or perhaps just straight-up asking if his answer was what they were looking for. The interviewer may have just said "yes" to be polite, but perhaps they would have explained that they were looking for a more specific answer. That's great that the author had a friend who was able to give him the honest scoop - most of us never have the luxury of knowing exactly why we didn't receive an offer.