Private business can fire without cause though. People get fired over the wrong opinion on Israel vs Hamas....what's the difference? Music ain't a government job.
I work for a private fortune 200 finance firm. All I can say is that or legal team is so scared of this branch of California law; that they mandate EVERYONE review it irrespective of position. We aren't even based there, but do business there. But still it's big
So If she can show evidence of a declined invitation and subsequent loss of recording time or fewer mentoring sessions then that's grounds for a huge fine in California. Everything from lost wages/contract-breach, to emotional dmg, to libel/slander, to legal fees.
Countless women have been victimized by higher ups at these entertainment firms necessitating a California-specific response. They put this protections in place because of the film and music industries, but it monkey branched into other ones like finance.
There is a reason why employers go out there way to give women, LGBT, and minorities a P.I.P. it's so they can create a sophisticated legal trail to counter such a lawsuit like this woman is giving, and I highly doubt Derulo was thinking that far, so he'd lose a claim of "at will termination" if she pulls reciepts in court.