Would you avoid downvoting an answer with a factual error, especially one that is central to the answer? Is it considered "rude" or something? Sure one can leave a comment noting the problem with the answer, but if you are noting that there is a key factual problem, why would you not also downvote? You can always change your vote after the answer is fixed. Of course then the person being downvoted might have a good guess that you were the one who did it.
It seems to me that if someone avoids downvoting for valid reasons, they just give more power to people who downvote for bad reasons.
I guess I'm trying to decide whether it makes the most sense to respond to factual errors (that are central to the whole point of an answer) in which of the following ways--
A) Leave a comment noting the problem, and downvote, because it's a bad answer, and the whole point of this site is to find good answers.
B) Downvote, because it's a bad answer, and the whole point of this site is to find good answers, but avoid commenting, because I don't want the answerer to guess that I'm the downvoter. (I don't like this choice. I'd only downvote with no comment if the issue were so glaring that anyone should be able to figure it out, or if the issue has already been addressed in regard to previous answers.)
C) Leave a comment noting the problem, but not downvote, because when you downvote answers with glaring key factual errors, someone eventually decides that you are not a positive person and starts downvoting all YOUR answers, so it's better just to decide that you will never downvote, ever, period, unless someone is being intentionally wrong or just is being incredibly negligent with finding the truth; otherwise leave downvoting to someone else.
D) Downvote, but only leave a comment if you think the person making the answer is likely to understand and agree with the comment and make an improvement to the answer. If you think he/ she will likely not understand or agree with the comment, don't bother commenting, because it will likely just tend to lead to an extended discussion in the comments, which is not the purpose of the comments. Particularly relevant to cases where the person has repeatedly disagreed w/ you in the past. (But, this can be avoided simply by not responding to their comment to your comment)
I see that some related discussion appears here-- Can we stop this "I dont know the answer therefore I downvote" thing?
Also extensively here-- Encouraging people to explain downvotes
The general trend seems to be that comments are encouraged . I suppose I will generally comment. Even if I know there is NO chance the person will agree with the comment and improve the answer, it's good to show other users what is wrong with the answer. (The fact that the originally poster of the answer won't likely agree with my comment, also means that there are likely other readers who wouldn't notice the problem if it weren't pointed out.) And I don't really care that much if someone decides to serially downvote all my answers for revenge.
Except of course in cases of just complete and utter negligence w/ discovering the facts-- then why bother comment as everyone else will understand the problem anyway.
Anyway-- thoughts of others?