If I sue my boss who was fired, do I have to abide by the arbitration clause in my employment contract?

This is based in California. My boss was fired for creating a hostile work environment and ual harment. Since she was fired, I have filed a civil complaint against her for intentional infliction of emotional distress and actual damages for extortion. Her lawyer is saying she is protected under the arbitration clause even though she is not employed by the company. I still work for the company but I am not naming the company in the complaint. Do I have to arbitrate with someone who committed unlawful acts during their employment, who no longer works for the company and the suit is against them personally for what they did while my boss (which was partially unlawful and partially against public policy)?