I saw a question earlier today that had been answered incorrectly, and most of the comments in the question were criticizing and correcting the answer given, rather than answering the question that had been asked. Is there a good balance between helping those that have asked the questions and helping those that have mistakes in their answers?
If a user tries to answer a question and fails to do it, did users who helped to make his answer correct helped OP? Yes. There is nothing wrong with trying to correct an answer.
If you still feel that the answer is wrong, just downvote - no need to flag it if its wrong, unless it is plain wrong and has to do nothing with question (however I doubt if in this case anyone will want to correct it).
i think it would be better if you would flag the answer itself as "Not an answer" for review purposes, and if you know the right answer post an answer about it, criticizing an incorrect answer would not help the community, rather you can comment to that answer if you want to correct the answer itself, helping both the user who posted the question and posted the incorrect answer was never wrong, we are a community and i think we should help everyone understand what the question really is.