The notes are probably from Priestap who is a cooperating witness.  Priestap likely took the notes in order to document what he was being asked to do by McCabe/Comey.  It was done to create a record, to protect the person taking the notes. Remember, we learned that an FBI official secretly reached out to John Solomon and Sara Carter in 2017 to express concern about what was being done to Flynn at the FBI.  Someone has a conscience.