It'd be one thing if the DS said "You are insane... these files DO NOT exist! Go ahead and check!" [And then FULLY COOPERATES w/ the investigation]  Just because they didn't open up all of their email for inspection? That doesn't mean they were doing X like they were accused of, they could have been doing Y but can't let that be known.  The Clintons got burned by Ken Starr looking in Whitewater for fraud and found Bill being a sexual predator. You don't talk to police(or investigators) and you don't co-operate.  https://www.youtube.com/watch?v=d-7o9xYp7eE