I just had my final round interviews with McK yesterday, all with Partners: two interviews went extremely well (both PEI and case, we had very friendly conversations and both said they were sincerely glad to have talked to me), whereas one went well for the PEI questions but I am afraid I kinda bombed the case. It was a a very quantitative case on financial services and, besides showing quite clearly my unfamiliarity with the topic throughout the case (I majored in political science), I made a substantial conceptual mistake in the last math question (he even told me before asking: please, do not get this wrong), after which I corrected myself but I did not get to calculate the final result because the second interviewer was about to enter the room; the end of this interview was quite abrupt.
Considering that one of the interviewers I did very well with is the Partner lead for national recruiting, do I stand any chance? How does the decision meeting happen, can partners in favour make a case if the third partner does not agree?