Legal Question in Employment Law in California

If the employee is at-will, then the employee can either follow company channels for complaints or start looking for another job. There is nothing else he or she can legally do -- absent proof of discrimination based on a protected class or retaliation for a protected activity (complaints about illegal conduct, for example).

If the employee has a written contract, or there is a collective bargaining agreement, then there may be something in those documents that can help.