They got flagged by users. We can still see what they wrote, see that it effectively willfully provided negative value to the conversation, and move on without it having to be a global conspiracy.
Not sure what you're alleging here. Is the suggestion that they're editing contrarian comments to be offensive so people flag/downvote them? Frankly, that seems like an ass-backwards way to go about suppressing dissent.
To be clear, if that commenter had been commenting in good faith, in detail, with actual citations and without profanity, or not using an account created expressly to make that comment, I think they'd have a fine chance to be visible (or at least not flagged).
