I would have to disagree with not thanking everyone who interviews you. I would think that your manager's pet peeve is in the minority. I was actually questioned by a hiring manager whether or not I'd sent a thank you to the other individuals and not just him. He felt it would have been a slip if you did NOT thank all those who took the time to interview and I agree. I have always thanked everyone individually with whom I interviewed with with one exception; if it was a group interview with many people in the same room at the same time, I addressed it to the senior person yet mentioned each by name thanking the group but if I interviewed with someone individually I would send a personal thank you regardless of their status. I have been praised by managers for doing so. I would think that "KO'ing" a candidate for doing so is out of line. Sounds like a power trip to me. Maybe others can give some input on this.