John Gruber wrote about Richard Stallman's disgraceful behaviour in September 2019 and again two weeks later. Read that, and maybe the original article too. This isn't about Stallman though, it's about the correction, so today the original article is a digression.
I quote the correction from the original article:
[UPDATE 7 OCTOBER 2019: Please read this correction regarding an erroneous allegation originally contained in, but now removed from, this article.]
That's the way to do it. I think that's the best correction I've seen on the web; frank about what the mistake was and that it was a mistake, frank about how and why it happened, apologetic, frank about what changes were made to the original blog posting to correct the mistake, posted as a separate article so it would be on the top of the home page for a while, and last but not least, with links in both directions.
Yes, I post this today because I'm annoyed about a different correction on another site.