I am sure you have done this in an interview.
You have been brainwashed by every single forum and case book to assume that McKinsey wants a framework and set of hypotheses, that you have stopped listening as carefully to the interviewer and simply providing hypotheses even when the interview is not asking for them!
This may sound ridiculous but we see this all the time.
R1 cases are usually done by analysts, associates and engagement managers. They follow the simplified style laid out in case books: uses a generic framework, ask questions and lay out your hypotheses.
Final round cases are done by partners and we do not follow this pattern. We even do cases where frameworks cannot be used at all.
In fact, it is interesting to observe a candidate ignore the partners request and simply provide a framework since that is what they were trained to do. Why would you ignore a partner over a book?
Listen to Felix’s second and third round of mentoring with Kevin Coyne. She makes this mistake even though he reminds her a few times to answer the question he is asking, which does not call for frameworks and hypotheses. Really, one of the few mistakes Felix makes.