I had a weird case where the team absolutely loved me, and had even extended verbal offer, but a surprise final interview with a low-level executive cost me the job.
Similar story: I once went through all the rounds with a company, it was obviously going great, then the recruiter mentioned all candidates need to get the thumbs up from some VP big shot so I needed to talk to him. Well, they scheduled the interview while he was driving, obviously in a convertible. Neither of us could hear each other, and there could clearly be no information exchange. I figured we'd just re-schedule, but the recruiter got back to me to let me know it didn't work out, and they wouldn't be moving forward. Crazy times!
I would have had to move across the country and they recently laid off 1000 (50%) of their staff, so in retrospect I figure I dodged a bullet, but wow!
I've found that the more rounds of interviews there are or the more people involved, the greater the chances of one person causing the whole deal to go south. I have been in similar situations. Six straight interviewers said to hire me. The seventh one said no and that was that.
