In my opinion those being sued behaved badly, so the lawsuit is appropriate.
I can see both sides. Hans has cheated in the past and admitted it. The fact that others THINK you are cheating gives you a psychological advantage. Hans goes out of his way to look sketchy in my opinion. He looks like a Bond villain. He’s aloof and unfriendly. He occasionally plays weird moves which freaks out the other side. He is honestly a good chess player but I think he has been playing a game other than chess here.