For example, here: Do (weaponized) lasers exist in the Star Wars universe?
@Zato posted a what-seemed-at-the-moment-correct answer, which generated tons of upvotes (10) stating "no such examples exist" - he did the research, but the only actual reference he had was Wikia (lack of references is of course not surprising given that the answer is "no").
Just to be clear - Aside from the fact that the answer is wrong - it's a good answer, with effort put into it, and I'm not intending to criticize the answer or the user.
After that happened, @DrewS actually posted an answer which found a canon example that showed the existence of lasers, thereby 100% proving the previous answer to be wrong. I even added exact book quote proving the assertion.
Voting is now only 2 votes on correct answer vs 9 (+11/-2) on incorrect answer
Even worse, someone upvoted the wrong answer AFTER I the correct answer was posted; AND after I commented on the wrong answer that it's incorrect.
What can be done to effectively combat such a situation?
None of the "normal" methods seem to work well:
Posting a comment on the wrong answer noting its incorrectness didn't stop people from continuing to upvote it.
Posting a new correct answer didn't bring enough upvotes to it to even remotely offset the upvotes on incorrect answer.
Flagging for moderator is useless because moderators 100% always decline flags about incorrect answers (I personally think should be within moderators' scope to deal with, but the fact of life is, it isn't)
Publicizing in chat doesn't help (didn't try for this one yet, but tried it before... zero or negligible effect on subsequent votes)