If you watch the Xbiz legal seminar videos they have posted on their site then you'll be able to hear the interesting back story from Larry Walters on this. Essentially, Karen Fletcher is very mentally troubled... to the point where her agoraphobia would prevent her from sitting in a courtroom (let alone serve a prison term). Luckily for her the feds were sympathetic... very luckily for her. I guess it's still a W in the governments record, though.
Edit: oops, I see this is mentioned in the article. Oh well, check out the seminar video anyway!