The high school thing was a mistake, but he makes a lot of good points on the collusion about the the letter. McClean was probably the source of the idea for the letter. Resigned from FBI just before moving to Del. where she was joined by Ford.
Congresswoman Echoo is the one who suggested CBF write the letter. CFB spoke with Echoo on Jul 20 and told her to write a letter to Feinstein. The letter was then hand delivered by Echoo's office to Feinstein's office on Jul 30. I suspect Feinstein knew about CBF 10 seconds after Echoo was done talking to her. It would suprise me if was months before..