If the act is immune, then it doesn't matter with whom the President had the conversation about the immune act - the conversation would not be admissible.

But I see the real possibility of a catch-22 problem. You suspect an illegal act is hiding as an immune act. Let's get closer to real life.

A president talks to his chief of staff. That is normally going to be about an immune act. But investigators think the conversation was about an illegal act. Perhaps they heard it from a secretary talking off the record. (Remember, conversations themselves can be illegal acts when part of a conspiracy. Yes, it takes more than just a conversation to have an illegal conspiracy, but conversing/colluding is one part of an illegal conspiracy.) If they ask the president or chief of staff to tell them about the conversation, they can say it's immune. Investigators need some proof that it is not immune to pierce that veil of immunity and actually talk to the people involved.

How are they going to get that evidence? So far, all of the discussion seems to be implying that investigators know the act is not immune. But how do they know that in a way the legally pierces the veil of immunity? How do they know that in a way that can be admitted in court?

--Peter