@UmbrellaHat
In the case of the 5th amendment, what would happen if you exercise that right when questioned by the police and then later in court come up with a cock and bull story reason, would your initial silence be disregarded, or would the fact that you remained silent initially be considered suspect by the jury? Sorry if this is off topic, but in the PA case might become relevant if pigs fly he is tried in a US court.
This will be a deep trench of US constitutional law ...
My understanding is that (depending on the exact jurisdiction) there is no blanket prohibition on a courts attention being drawn to the pleading of the 5th and a subsequent story. However it's nuanced by the evidence the prosecution brings.
At the end of the day the default position is the accused walks free if the prosecution don't make their case. There's no onus on the defence to prove anything.
However talk of PA being tried is jumping the gun a bit. Currently he is being sought as a witness. And as such his evidence would need to be given in a way that is fair to anyone who subsequently faces a criminal trial. There's a bedrock of US law that simply can't be fudged - the constitution. And that is pretty explicit about people accused of a crime having a right to question their accusers. So for in the case of PA, while it might be nice to have a chat and goss with the nice folks from the FBI, anything they get can't be used in court unless he is also there to verify it.
From memory you can get sworn testimony into a court record, but it's not the norm, and only used when a witness is dead, not playing hide and seek.
So the bottom line is there's fuck all point in the FBI wasting air miles (the irony) to speak to Andrew if they wish to use anything in court.