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This should be a separate option. I never downvote comments which differ from my opinion, but I always downvote comments which differ from fact.

I find the sub threads the correct things in a helpful (kind tone, provide citations), however

I agree with this. When someone posts something blatantly false in a matter of fact way I feel downvoting is a public service in the sense you are averting eyeballs from it.

I'd also say that if at that point no one else has corrected the person, you should.

Why don't you just provide a correction?

Some comments are wrong but interesting, it's a common error or an error on a strange case. I try to vote a correction reply or write a comment explaining the error.

Some comments are extremely wrong, as "If you plant a fried potato, you get a fried potato tree." I downvote this kind of comments.