Is Revising an Article's Contents, Then Pretending the Change was in the Original Ethical?

Writing ethics. In the new online world of writing, writers can, after they've submitted their article, go back and change it. If they do, and they then pretend it was unchanged, in comments, is that unethical, dishonest and deserving banning, meaning loss of continued privileges to submit articles and comments. 

Here's the scenario:

Someone posts an article.

A reader criticizes the article for leaving out key information or any supporting links to support claims. 

The writer goes back to the article, adds what the reader criticized was missing, then responds to the comments criticism saying, "You didn't look at the links I had there." When in fact, there were no links in the original version. 

It seems the right thing to do is to make the changes, then THANK the commenter for the useful criticism in an addendum to the article. 

It seems a dishonest, or disingenuous thing to do is to suggest that the commenter missed the links that weren't there and not make the changes.

We're not talking about spelling corrections here, which I don't think need to be supplemented with an addendum. 

 So, the question: Is it unethical dishonest or both to make changes without letting the reader know, then acting as though the changed content was always there?