Actually getting tenure can be pretty tough and very political. Presumably she estimated that her political circumstances were bad and it that it would be better to start fresh than try turning things around, which is a rational decision that many assistant professors should make but do not.
The article certainly doesn't make it look that way. She joined in 2004 and left in 2006. Way too short even for a five year tenure clock, especially when she very much needed the health insurance.
Sure, but leaving without securing another tenure-track position? You can't reset the clock, still, leaving early is Not A Good Sign you know how to play the game.
