the downvote was there before I made the edit

Interesting. I wonder what whoever-it-was didn't like. Oh well, never mind.

LW provides the * to show that the post is edited.

Yup. And that tells you nothing about what was done to it, so if there's a comment saying "blah blah blah 2+2=4 blah blah blah" with a star, and a reply saying "I'm not sure your arithmetic is correct" there's no way to know that it used to say "2+2=5".

and needs thinking to be parsed correctly

OK, now I'm going to stop trying to be tactful.

Your original comment was simply incorrect; the only way to parse it "correctly" is to ignore the way the English language actually works; it just didn't say what you intended it to say. I didn't suffer a "failure in reading 201", I didn't fail to think, I pointed out that you had suffered a failure in writing 101 and I did it tactfully so that (e.g.) you could correct what you wrote and call it a clarification.

In response to which, you edited your comment to make it look as if I had made a mistake, replied to my comment as if I had in fact made a mistake, and are now doubling down and attempting to make out that the problem was my inept reading rather than your inept writing and that you did nothing wrong in making me look like an idiot for trying to help.

Sorry, but two consecutive defections earns you a defection in response. You did wrong, you tried to hide it, and you acted so as to make someone else look bad for it. I'd been assuming that last bit was unintentional, but your latest response is making me reconsider. Anyway: Please don't do that. It's rude.

(Of course it's also an extremely trivial pair of consecutive defections and it's not like it matters much. I hereby acknowledge that it doesn't matter much. But, still: Rude. Don't do it.)