I've walked out of 1 potential interview. I turned up and they handed me an application form to fill in there and then, when they were interviewing me on the strength of my CV. It became clear it was a delaying tactic as they were late. I found this unacceptable, asked the secretary to pass this on, walked out and sent them my travel expenses.
Another time, the guy interviewing turned up, went into a room, I went to follow him and he held his hand up and said I've just got to read your CV first. Wot! Anyway I liked the sound of the job so I stayed but it became clear during the interview, that had he read my CV prior to me turning up, he probably wouldn't have invited me as I didn't fit.
As an interviewer, I remember asking a woman what her reaction would be in a certain situation, how she would handle it. She replied by saying. well she wouldn't get angry at first......
During another interview, it became clear the guy we were interviewing was waaaay overqualified for the role. I looked at my colleague, who'd vetted this particular lot of CV's but he seemed happy to carry on, being very interested in the stories the candidate was telling us. I was not, I was embarrased and stopped the interview and apologised, explaining the role we had to offer was not suitable for his experience.
Another time, recruiting for a Cobol programmer we were struggling to get someone who would fit the role. The agency pressed one guy who I was reluctant to see but there being a dearth of candidates, eventually agreed. He travelled nearly 200 miles to us and started of by telling me of his dire circumstances. As I thought, he didn't fit but I felt enormous pressure and responsibility to take him on due to his circumstances, in fact it was like I had the full weight of his responsibilities on me. It was the hardest thing I've done to say no to him and then explain my justifications to him on the phone and refuse his supplications to be given a chance. It still haunts me to this day and made me take all subsequent interviews a lot more seriously.