I had the weirdest let-down after an interview this summer. Like the author I thought it had gone fine but something entirely else was going on. The interviewer let me know the reason I was not chosen was that I used agressive micro-expressions and lacked diplomacy. I don't know if my love for technical excellence (a topic broached quite fully during the interview) or my anecdote of an anti-pattern at a previous employer was really presented with toxicity but my takeaway is that sometimes you have just been set up for failure and nothing can be done to salvage your chances.