Durham was an inspector, not a prosecutor. His only role was to dig and expose, leaving prosecution up to someone else. And how does one prosecute when the whole lot of Congress and multiple White House Admins are responsible? The shit we see being exposed today goes back decades. How does one man effectively prosecute all of that? He doesn't. He digs, exposes, and let's future legislators do what they will the info he's uncovered. His mandate was an Executive Branch mandate. If all of this has to be done by the book, then any such mandate cannot include prosecution for the crimes being exposed. It would be too easy for our Enemy to cry political foul if it was.