I gave my first talk at university chicago in the economics department when i had just finished my pach di. I put up my power point slides, and there are seven hands up in the audience. If you let this person get through their talk, then of course they will address your methodological objection. And it is more efficient for them to get there than for you to interrupt. But if you selfishly want to ask your question on the tatle slide, odds are that's not the most efficient way for information to be transmitted.