What about the grounds that it's untrue? She needs to learn to make a stand based on conviction and truth not because it was too mean. She's indicating that it would be OK if it was a little less mean which probably isn't true. So she's in essence using a lie to prevent another lie?
Because then she would be arguing with her employer and that is a no-win situation. Frankly I think it is good to have some folks behind enemy lines.