I have no idea what you just said but, it seems argumentative.
You cannot use, possess, trade or sell something you are not lawfully entitled to, for any reason.
Federal law, state law, telecom law, and all kinds of other laws.
In California, you may not, record someone without expressed and explicit consent from both parties and anyone in possession of an unlawfully obtained recording is just as much barred by law, even if the NBA contract said “We can use any means, as a reason or excuse, to deprive you of your property”.
To give several examples, I can take the deposition of a person who is alleged to have embezzled from my client, and I don't have to give them a 5th amendment warning, and what they say can be used against them later in civil or criminal court. I can violate their First Amendment rights by refusing to allow them to be published on my web site. I can violate their Second Amendment rights by refusing to let them carry weapons on my property. I can gather information on them, maybe even illegally, and while I might be prosecuted for trespass, the evidence is still admissible. I am not the government.
Similarly, if a citizen gains information illegally from a criminal, it can be used in a criminal proceeding, because the state has not violated the criminal's rights. The bill of rights protects us from actions by the state.
Meanwhile, you have an entirely different situation presented by California's law on recording. There, the State of California passed a law making it illegal to record private conversations without consent of all parties, and made the use of such recordings illegal in any proceeding. Doesn't matter if the later proceeding is a criminal or civil or small claims, or if it is a private citizen, a sports league or the government who seeks to use it. It cannot be used, no matter the innocence of the person who wishes to proffer it.
You were using concepts that pertain to the 4th amendment to analyze the statute, and those don't really apply. The Sterling situation is all based on a statute and what it says. If it were not for the statute, the mistress could have recorded him to her heart's content, and used it however she wanted. A government needs a warrant, but a citizen doesn't. This is not a constitutional issue, but a violation of one law.
I linked to the law in this post way back in April. Take a look at that if you want to know what it says specifically.
I hope that helps. I was not trying to argue but to elucidate.
By the way, I love this! I think I will have to find a way to frame it on a wall somewhere.