Sounds like the start of a legal defense to me.
Remember... polygraphs (at least not the types that were conducted) are admissable in a court of law.
Unless there is witnesses or papertrail, this might just be her play to stay out of jail WHERE SHE BELONGS.
Wasn't there a report that when confronted she confessed, or admitted it???
There is a Washington Post reporter who can rot in jail until she divulges the source. Will she rot in jail or will she rat the rat.