You can request a change of an article's rating now: https://github.com/civitai/civitai/commit/096914b13c3967064a0cb9429b99a0aa37560119
Previously there was no (easy) possibility to dipute a rating determined by the article scanner.
To request a change of the article rating just press the button "Request rating review" at the top:
Then you can select the article rating you suggest and write a comment:
Unfortunately article rating guidelines link shows "page not found" right now. Finally a new feature I find useful (given that it works, remains to be seen).