If you are on a conference call with a large group and you are directly asked a question you don't know the answer to, don't panic and simply sit in silence. Eventually, someone else in the group will chime in and then you simply say after they are done, "Apologies everyone, I was on mute and was talking to myself there for the last few minutes!" Then, say that you basically agree with what the person who chimed in had said, "subject to some caveats that are best taken offline." Silly mute button.