Legal Question in Employment Law in California

They do work for independent contractors just as well as for employees, however "hostile work environment" is not the same as that phrase has in normal language. It is a special legal doctrine that allows a person who cannot show direct discrimination based on race, gender, etc., to show employment discrimination by other acts that result in a work environment so hostile to their protected class that it forces them to quit or make them unable to do their job, just as if they had been fired for being a woman or black or whatever. Examples are things like the first woman working in a all male machine shop who is subjected to nude pictures in the lunch room, sexist jokes, unwelcome touching, etc., and the employer does nothing, or the only black secretary in an office being subjected to racist comments and jokes and other direct hostility for being black to the point where he can't do his job. Your situation is not a legal "hostile work environment."

Hostile work environment claims can only be based upon illegal discrimination, harassment or retaliation as defined under the ADA [disability], Civil Rights [age, race, sex, ethnic, religion, pregnancy, etc], FMLA [medical leave], Whistle-blower, or similar statutes. There no laws against 'unfair treatment', poor management, gossip or drama.