OK, you're a varsity coach. If someone caught you on record barfing up racist garbage--or something else that similarly calls into question your influence on young people--then put it up online and you lost your job over it and your defense was "I call bullshit that was meant to be private," the "breach of privacy" (and how much of a breach is it? Are there many closet/ secret racists? Isn't a racist usually fairly satisfied with their take on the world?) wouldn't really move me, and I'd consider you 100% to blame for what happened. I'd see that as a victory for accountability, not some horrifying sea change that will eradicate my private life going forward. You say "dumb," but I'd argue that in fact no, no one on the internet would care about you or I saying something "dumb." They may, of course, care if we are saying something hateful, abusive, prejudiced or similarly socially unacceptable--but even then, I'm not a varsity coach. What could I say that anyone would even bat an eye toward?
Further, you expressed this event as some bad omen for freedom of expression, which my post intended to disagree with. Yes it happens to famous people occasionally now, but it just does not happen to John Q. Internet-User. Yes, the scenario you describe could happen; but more often than not when these things gain internet traction it isn't because some librarian got caught by a nefarious dickhead saying something backwards and misinformed and got herself fired by an evil internet tidal wave. It's because someone in a position for the community to care about got caught saying/ doing something that isn't OK even in private and called into question whether they deserve the community's continued support (NBA owner, varsity coach, etc).
Ultimately, when you say things like that, you incur consequences. That one of them was a person looking for leverage taking those monologues as an opportunity isn't really an issue to me. Of course she did. That's the kind of bad shit that happens when you put that out into the world. Standing around wringing one's hands about how awful the gold-digger is and how this is all an affront on our privacy misses the point. This is a good thing to me--it means people give a shit about someone being blithely racist, and there are actual negative social consequences to putting that out there. Putting her motives aside for a second, the reason she recorded it was because she knew people would hear it and not put up with it (creating leverage for herself), which is a good thing.
So yes, I am very comfortable living in a world with increased chances for someone like Donald Sterling to get caught as the person he truly is, and for the reaction from the community to be a rejection of it and not an outcry over his bruised privacy.