An answer for a question solves what the user wanted, in particular. However, in rare cases, user might get a problem. The answer might have a side effect, that too rarely. The answer might have left an exceptional case unanswered. Or, a user finds that answer has an issue long time later it has been answered. Should it be downvoted?
You can downvote any answer for pretty much any reason you feel appropriate. There are no strict rules. This may be because it's simply incorrect, but may also be because it's technically correct but doesn't do a good job at explaining things. It may also be because you don't like the formatting, or if there are too many typos. It's really up to you to make the judgement.
I have often downvoted answers for exactly the reason you've described: the answer is technically correct, but is missing some information which may come back and seriously bite someone who follows the given advice. It's usually best if you also leave a comment explaining this so that the answer can be improved, but you're in no way obligated to do so.
The only thing that's not allowed is doing stuff like targeting a specific person with up/downvotes. You need to judge answers, not people.
I don't think people should necessarily down vote anything unless its explicitly wrong. I've noticed, mostly on other SE sites, that a lot of the tech world knows the answer but is horrible at explaining it. Even worse, we tend to have a lot of people who like to rebut answers with, "Well technically...". I don't know if it is smugness or lack of understanding their audience, but these types of responses tend to hurt learning. I know there have been many times where I'll put a lot of detail into an answer and on purpose not include something. Usually its an outlier case that will only confuse the person asking the question and isn't pertinent to their query. Then someone will swoop in, down vote and create a post poorly explaining the nuance case and make life much more difficult.
Is there a way to fix this? No. People will still act the way they act.