There isn't a lot of room between saying it in a way that makes the threat clear to the politician and saying it in a way that doesn't make the threat clear to the New York Times reporter listening to the recording.

Also, the NSA could just kill you and make it look like a heart attack. As could the mafia, Goldman Sachs, Ted Bundy or AT&T. Doing the right thing is the right thing even if bad people aren't going to like it.