There was only one statement in this thread from a user saying that the allegations were not correct. But even so, Nutildah added further evidence.
However, even knowing that Copyleaks can falsely work, you can look at the user's early posts and see if all the other posts were as good as the ones that are suspected of using an AI tool.
As you can see, there were no false positives in this thread, and the moderators successfully removed all posts that were reported.