Just say "I do not know" and do not waste your and my time with monologues full of guesses and sort-of-related-but-not-relevant info. It does not help. It just wastes time.
If you say, "I do not know" we can work on it. We can file it as an open question until you know. We can ask somebody else or search for information.
And btw, the answer to "Will mistakes sometimes happen" question is: guesses cause them very often and they slow analysis a lot. You just do not see it, because I can not go to you and show you all your wrong guess mistakes. I have to smile and pretend that I trust you while triple checking everything you say which again, slow down analysis.
Working with people able to say "I do not know" is way easier and faster.