I have read the case and the grounds of that decision was based on an employer trying to force an employee to take a political stand within their hired position. What you are trying to argue would result in someone not being able to have their position terminated over their action that could cause negative impact to their employer. For example, General Petraeus would have legal grounds to be let go regardless what his actions brings to his position. Of course, this isn't even bringing in the fact that this person resigned and her position was not terminated