I was fired by my company for an angry, but truthful email my spouse sent to my boss.?

I work, or worked, for Wamu. The background is that I as an assistant manager was left more often than not to do all the work while my manager took excessive time off (by this, I mean she would take off in the middle of the day, using sick pay, and/or schedule tons of vacation for herself while begrudging everyone else's desire to more freely use the vast amounts of vacation they built up/earned). In addition, the few times I used sick leave, she would call me up, brow-beat me, and even if I had the flu, would try to pressure me to come in. I recently began the transfer process to a different branch about 40 miles away. Due to Wamu becoming JPMorgan Chase, there were snafus, including them losing all the information I'd submitted and having my start date at the new branch moved back at least twice since they wouldn't accept me at the new location without the information. With the last delay, my new set of bosses were sympathetic and were willing to let me report to the new location since we'd by then already moved and had our daughter set up in her new school. However, my old branch manager (the self indulgent one) initially told me I technically "still work for me" even though she knew I'd have to deal with dropping my daughter off at school, then travel 40 miles away, then worry about who'd pick up my daughter at the 3pm let-out time when I didn't get off until 6 or later. I asked if I could just use some of my vacation time while I was waiting for the transfer to become a done deal and she obtussively said "no" with a "that's your problem" attitude(this just a week after giving me a "farewell dinner". After all this frustration, I was so stressed, my arm became numb and I began having chest pains, so fearing it might be a stroke or heart attack, my spouse brought me to the emergency room, where we stayed for about 4 hours. It turned out to be stress and pinched nerves, but we were there until one in the morning, so not only did this affect me, but my spouse as well, who had to call in sick to HIS place of work the next morning as well since we were up so late. He, having patiently seen similar scenarios with my former manager (the self indulgent one) countless times before and biting his tongue, could remain silent no longer, and sent an angry, but factual email (no name calling or swear words, just the facts) to that manager and pointed out her abuses. She in turn forwarded it to Human Resources. They used vague wording stating the letter, which I myself had not written, was "too much" or "went over the line". I was then terminated for an email I did not write. My only "crime" in this is that I silently agreed that the content was appropriate. I live in California and was under a "binding arbitration" agreement in which we as employees cannot sue Wamu/JPMorgan. However, we can personally sue a manager for abuse. With these facts in mind, what are my legal recourses?