that’s pretty normal and potentially structured to see how you act under pressure. Candidates at final rounds mostly know how to crack cases (they have already done one-two rounds of interviews), thus partners pay more attention to you alignment with the company and communication. Looking how you react under pressure/under impatience is a way to test your communication in a common scenario for a consultant (dealing with impatient clients).
They key for your reaction is to maintain confidence and show you can proceed with your analysis without feeling too much pressure. Thus, you should not necessarily adapt to a faster communication at the first signs of urgency from the other side. It could be a simple test to see how you react. And in general, it is better to keep control, go slightly slower and provide a correct analysis then speed up, show anxiety, and provide wrong/unstructured analysis.
The best way to gain additional time/slow down is to:
- Use ice breakers for challenging questions (eg rather than keeping silent 10 seconds say right after asked “That’s an interesting question”, even if you don’t know how to structure on the spot)
- Recap the situation until that moment
- Ask a minute of time to structure if needed
Finally, although as mentioned you should not jump to speed up the process immediately, you should also be able to read the messages from the interviewers: if you get repeated signals you should go faster, or concentrate on a particular area, it would make sense to follow the hint.