is it possible to eliminate at least one doubt from the overseers head here by showing the instruction from your provider to ban both this user and DGUDGUDGU? If you can't show it publicly but willing to show it privately to a limited eyes, I will take the honor, suppose other overseers agree to it.
I second this. This is a really good suggestion that will not only boost the credibility of the casino in question's claim but also remove a big part of the doubt. You (the casino in question) have to do this otherwise, there will be more reasons that you cant be trusted.