The underlying principle---legal representation costs money even if you're in the right---would still hold.
> I have to assume that he has covered his tracks well enough to remain anonymous.
No you don't. John Doe lawsuits exist. You would be on the hook for legal and possibly detective fees, but if you start a legal process GitHub can be compelled to turn over what records they have about the perpetrator.
> Thanks to my experience with Mr-Steal-Your-Script, I am seriously considering keeping any additional code that I write to myself.
That seems wise.
> If you have found this article worthwhile, please share it on your favorite social media. You will find links at the top of the page.
I'm not sure I want to risk it at this point. The article is copyrighted all rights reserved, and we've seen how the author feels about their publicly-posted information being shared.
Why?
Just not a person that I can assume won't slap me with a takedown notice if they don't like the context in which I share their work. I don't have time to want to bother to deal with takedown notices, and it's a wide, wonderful internet with all kinds of other information I could be sharing. The safest course of action for me is to skip it.