If I may offer a general suggestion, new official; there are really only two answers to the question, "Didn't you see that" (or any of it's endless variables), and both answers take you (and the questioner) to exactly the same place. Either you didn't see, whatever the questioner thinks he saw, or you did observe EXACTLY what he saw and reached a different conclusion than the conclusion he made.
Depending on how politely the question was asked, YOU may choose to explain why you arrived at a different conclusion, but that's YOUR option. If the question is from a HEAD Coach, he has the option to request (a charged) Time Out to review a rule interpretation with the Referee, with the understanding that if his conclusion, and the discussion, results in a reversal, he will not be charged with the TO, and the appropriate correction will be made.