Casey is not protecting anyone. The assumption that she is staying quiet to protect someone is based on the assumption that she thinks and views the world the same as the rest of us. She does not. call it what you will, Sociopath, Psychopath, pathological liar, narcasistic personality disorder. It amounts to the same thing. She is keeping quiet because she does not want to talk. Plain and simple. When she does open her mouth, it is pure lies. Because that is what she does. If challenged on her lies she simply clams up. She cannot grasp or deal with someone not believing her lies, anymore then the rest of us can grasp why she lies in the first place.
In her mind she is simply staying quiet until this all blows over. She does not plan far ahead, she is not concerned by things in the past. No guilt, no remorse, no empathy, no compassion.
That is who she is.