If Sterling knew he was being recorded, it was not only legal to record him, but it was legal to release the private conversation to the media.
I read an article a couple of days ago about private recordings under California law. I'll go back and see if I can find it. From memory - It takes more than just knowledge of the recording, it takes consent.
And the little tart muffin has 'said' he consented, but has shown no proof of it.....which makes not only the recording itself illegal, but I believe the publication of it as well.
Which makes HER liable for the recording and the consequences of it.