Unfortunately nothing you describe is unlawful or gives you the basis to legally contest your termination. Most private employment in California is "at will". This means you can be terminated for any reason, or no reason at all, at any time so long as it isn't based on discriminatory reasons (i.e. because of race, sex, national origin or another protected classification), or your having engaged in a protected activity, or in violation of the terms of a contract or collective bargaining agreement.
Being “at will” also means that the employer is not required to provide advance notice of a termination decision and is not required to justify the decision with “good cause.” Sorry...
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As cruel as it was for this supervisor to fire you and the owner to back him up, if you are regarded as an "at-will" employee, there is little you cab legally do unless you have evidence that you were fired for an unlawful reason. A personality conflict is not an unlawful reason.
If the owner is claiming you were fired for misconduct, be prepared for a fight when you file for unemployment benefits because misconduct is a basis to deny those benefits. It may be worth your time to consult with an employment law attorney for a better assessment of the circumstances and to discuss how to prepare for an unemployment appeal should that become necessary.
They say you get what you pay for, and this response is free, so take it for what it is worth. This is my opinion based on very limited information. My opinion should not be taken as legal advice. For true advice, we would require a confidential consultation where I would ask you questions and get your complete story. This is a public forum, so remember, nothing here is confidential. Nor am I your attorney. I do not know who you are and you have not hired me to provide any legal service. To do so would require us to meet and sign written retainer agreement. My responses are intended for general information only.
I agree that you should speak to an attorney. It is legal to terminate an employee because you don't like him as long as the reason you don't like the person is lawful. You used the words personal hate and judgement. You should explore that with an attorney. Many will provide free consults.
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