Insurance companies are regulated at a state commissioner level and in theory are supposed to be neutral. But, it's hard to say for sure any being is entirely neutral. I would recommend looking at customer reviews and reports for your specific area, as that will give you the best information. From my own research, AAA seems to be about average on handling claims. Remember, if you feel you are being treated infairly, you can contact the insurance commissioner of California
and complain. Here
is some information on the claims process.