It begs the question as how a lower level operative in the intelligence service has access to the contents of a telephone call between the POTUS and a foreign leader. Was the presidents phone bugged? I see no reason why anyone outside of the White House should have access to these conversations. It is clear the whistle blower did not directly hear any of these conversations and everything is pure hearsay colored with partisan bias and deliberately leaked to the media.
No, there are agencies such as... Those involved with national security who have “lower level” operators that take notes on these calls.