It never ceases to amaze me how little people actually know about the first amendment.
The first amendment reads as follows "Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the Government for a redress of grievances"
None of what happened, violates his first amendment rights, since the NBA is a privately owned organization. Add on top of that, it appears at least that Donald Sterling signed an agreement that gives the commissioner the power to take the actions he has.
Ironically, assuming that V Stiviano doesn't admit to recording him, the first amendment will indirectly protect her, since it could be argued that TMZ does not have to reveal their source.
Even when you look at how broadly the law has been applied at times, none of it comes close to this situation.
What alarms me, is the lack of understanding of our constitution. Freedom of speech does not protect someone from consequences that come from the public or private groups. Go to work tomorrow and tell your boss he/she is a fat mother ****** and you want to kill them slowly with a paper clip, then when you get fired, try to find a lawyer to take your case.