So, in summation. You attacked him, personally, on SM.
And are now outraged that this has been shown to your employer, because he identified himself (well of course he needs to do that) when he contacted them, and he said (in effect) "I question if she should even be in the role, in my profession, this conduct on social media would result in dismissal" (which might be true, or might be bollocks, it's actually irrelevant because you aren't in his profession)
Your employer has ignored the lot and it's a closed issue.
What's the problem?? Don't go out of your way to attack people on SM then be professionally offended when it backfires? There's no breach of data of any consequence, and here you still are banging on about solicitors, unions, etc like "she who has been wronged".
It's clear from your retorts to people that you aren't taking much on board and feel absolutely justified in what you've done, whilst furious that someone might hand you back a dose of your own medicine. Take some accountability and maybe a life lesson about not saying unpleasant things and expecting no recourse. As my eldest would say, "fuck around, find out."
You're coming off looking a lot worse than he is. But evidently, no one on this thread is going to make you see that.