Should my minorly wrong answer be replaced or appended with my improved answer?

Question

In this question, I will be focusing on this answer as an example.

So someone asked a question regarding layouts with CSS, and someone gave a solution to do with Flexbox. Now, the answer technically was a valid one, and although it didn't exactly accomplish what was asked in the question (but it was close), it was a useful answer and could have possibly contributed to people looking at that question in the future.

However, after I pointed out the minor issues with the answer, the answerer went ahead and completely edited his answer to consist of a different method of accomplishing the required outcome to the point where it was not recognisable anymore to the old answer.

This caused the comments on the answer look completely out of place and off topic, as well as the loss of some valuable information that could be helpful to those with similar questions in future.

I told the answerer that he shouldn't do that, and instead, should add a new answer or include both methods in his answer due to the aforementioned reasons.

I just wanted to know if I was right in doing so, or if the answerer was correct in replacing his answer.

P.S. The answerer just edited his answer to include both as I told him in the comments, but I am going to ask this anyway because it seems like a good question to be on this site, as I couldn't find one discussing this.

Answer 1

Comments are, have always been, and always will be, transient second-class citizens. When it comes to consistency between posts and their comments, the posts always take priority.

If the author of the answer chooses to edit the answer, even significantly, that's entirely their choice and it's perfectly acceptable. Editing answers should never be discouraged for the purpose of keeping the comments consistent. There is absolutely no problem with any edits to an answer that cause it to be in conflict with its comments, especially if those edits are an improvement to the answer.

Instead, either let the comments stay as they are, or if they're too noisy, raise a custom flag on the post requesting a comment cleanup. If it's just a few comments you could also flag them as obsolete.

Now, nothing to do with the comments: As for the loss of valuable information in the answer, that is the author's choice. So if you want to approach this, rather than taking the angle "you shouldn't do that" (because that's not really a rule presuming the edit was intended to improve rather than vandalize), you may instead want to take the angle "hey, I also found the information in your old answer useful, would you consider adding it back", or even adding your own new answer containing information you felt was useful that is no longer present in any of the other answers.

Answer 2

If it's minor, you wouldn't change it beyond recognition. If the changes are substantial, better yet make it a question. Sure, why not?

It's not vandalism. It answers the question better... I don't see the issue. I like having the process of doing it wrong before doing it right visible, but it isn't essential.

As for comments - if they're useful, they should be in the post. otherwise they should be considered transient.