The linked answer has just been deleted, but can (currently) be viewed here https://web.archive.org/web/20191105085319/https://meta.stackexchange.com/questions/335373/what-did-monica-do-to-violate-the-coc#answer-337557. It contained:

• A quote from the article on The Register that repeated the statement made by the StackOverflow Inc. director who sacked Monica. This statement claimed Monica broke the CoC, but did not clearly explain in what way it was breached. The answer treated the director's statement as objective proof that the CoC was in fact breached.
• A quote from a Wikipedia page explaining what preferred gender pronouns are.
• Another quote from the Register article. The answer claimed the quote, "there are multiple ways to avoid misgendering and we should not require a specific one", was from Monica and represented her position. The answer then claims that this quote demonstrates opposition to preferred gender pronouns. That claim appears to misrepresent Monica's position (she, like many professional writers, habitually avoids all pronouns in formal writing where possible, for clarity). It also misrepresents the current CoC, in which it is clarified that "You can often avoid using pronouns altogether" and that there is no rule against writing that naturally doesn't contain pronouns so long as it is not singling out particular users or groups, while moderators, who are held to a higher standard, are not allowed to "conspicuously" avoid using pronouns they "find uncomfortable".
• A long quote from some blogger completely unrelated to Monica or this situation, who was writing against preferred gender pronouns. It was strongly implied, without any evidence, that Monica was somehow in agreement with this completely unrelated blogger.

I didn't vote to delete the answer because I think it's useful to see concrete proof of how the unsubstantiated public allegations StackOverflow Inc have made are causing ongoing damage to Monica's reputation.

The user who posted the answer was active on many SE sites, with nearly 10k reputation here and nearly 40k on Stack Overflow. In the comments, the user said they trusted what was printed in The Register because it's a long-standing news site and has many Twitter followers.

The answer was clearly not what it's billed as in this question. It repeated an allegation, treating the allegation as proof of guilt, then appeared to try to tar Monica by association with completely unrelated individuals.

The same thing you do with answers containing misinformation:

You downvote it.

But what do we know? Who are we to say what is and isn't a lie, until all cards are put on the table? Who's to say things will be better if all cards are put on the table?

Stop speculating, and look at what we know.

What systemic lies are there that you think there should be done anything about? Everything the public knows is basically:

1. Monica asked for clarification when a CoC update was being discussed in a private chatroom (TL)
2. Monica was demodded.
3. A SE employee talked to the press about it, and referenced her by name as having broken the CoC.
4. Nobody bothered to tell Monica what she actually said that was supposed to break the CoC.

There are two ways of upholding quality within any community on Stack Exchange Network:

• You use the existing means to give feedback. As in: you upvote "high quality" input, you down-, close-, delete-vote content you consider "low quality". Ideally, you leave the OP a comment telling them "what to improve". Sometimes you click on "flag" and report the corresponding post accordingly.
• When creating content yourself, you take a hard look before hitting the "submit" button. For example you avoid using loaded terms such as systematic lies. Because that term is your opinion, but you use it as if it were a fact.

Nonetheless, you are "correct" insofar that the voting system is far from perfect. Sometimes people vote without really reading everything, they see "something" in a post, and that results in a quick vote.

But the main point of this place is that quality is defined via consensus. Sometimes that is frustrating, but that is how things are here.

Finally note: answers with high vote counts often have high view counts. So, doing that downvote, and then writing fact based comments that outline the deficiencies of a bad post ... those comments will get many views, too. And when the comments are of high quality, they will get upvotes, too. Allowing you to "add" your counter arguments right next to the content you consider "low quality".