The big problem with all terminations is that the default is Employment At Will, which basically means that all terminations are presumed to be legal unless/until the employee can prove that they are not. You mentioned EEOC. They enforce a law called Title VII, meaning that the employee claims that the termination occurred because of their race, gender, national origin, or a few other legally protected characteristics. Ratting out your boss is not covered by this law. This is CA, so there is a remote chance that there is a Public Policy exception but you really need to talk to a local attorney who specializes in termination law. If I was to make a bet based solely on what you have said so far, I like your employer's side of the case better then I like yours. A lot better.

What you really are looking for is a "whistle blower law", which exist, but which tend to be very limited in scope. Remove that, and remove a Title VII or similar protected class argument, and you are left with a very weak Public Policy case.