If you screw up so badly that you've lost months of work, you should probably be fired, and why should your employer care then what files might happen to be on your machine after you are gone? Most times, it's not worth it to pay someone to go through them.
Let's posit that Lois Lerner may or may not have been an OFA cell member acting on instructions coming from outside the IRS. Lois might very well keep email on her local hard drive to avoid the regular IRS email server backups. Or, she might have done it because there were limits on how many emails she could save on the IRS server. Or maybe that's just the way that IT setup her email.
Then let's say the conspiracy gets hot. Or maybe you have done what you needed to do, and realize the inevitably of discovery. It should be an easy matter to trash your hard disk and destroy the evidence. Your OFA cell leader can get you instructions on how to do that. Sometimes hard disks just crash. It's happened to me a couple of times.
The Washington Post did get its hand on some emails from July and August 2011:
Lois gets philosophical fairly quickly:
"We can only try - but it may be too late - don't they send them off to the hard disk cemetery?"The final email is innocuous enough:
Thanks for trying. I really do appreciate the effort. Sometimes stuff just happens.There is a noticeable lack of swearing. Did she really want her hard disk recovered, or just to exhaust every effort to confirm that the information on it was in fact gone for good?
Either way, the story is entirely believable.