Barr is in charge of a more important investigation. There's no doubt Barr has seen 10 times worse material than this. That's what Durham needs to use to prosecute conspiracy that most of the perps will plead down to simple negligence.
There's no way the deep state will let their own go to jail, or at least not the serious players. Barr has to play whatever cards he has including these notes to get what he can.
Shocking, but is this really surprising after 7 consecutive 4 year terms of horrible administrations?