I often find that I'm not "FGITW" to a question. I also find that often an OP or user finds an answer to a question that looks good on paper, but hasn't been tested or fails when being tested, but upvotes it anyway, pushing other legitimate answers down. Is it OK to ask OPs to look at an answer in the comments section?
If an answer turns out to be incorrect, then you should comment on the answer and downvote it. You should trust that others will look at your comments and determine whether an answer is accurate (or not).
Whether others upvote it or not is something that you should not be worried about.
However, if you make a significant change to your answer and think that it has become more accurate than other answers, then you could make such a comment as there is a chance that the OP may not have seen the changes.
If you find a answer more correct than another one, you can leave a comment to the more correct one, explaining why it is so; you could also leave a comment to the answer that is partially wrong, explaining why, or when it is not correct.
I would rather avoid referring to the OP; I would write a comment that explains to the future readers why the answer is not correct/completely correct, hoping that the user who wrote the answer corrects it, or makes it clearer.