Their defense makes things worse, is the point OP's trying to make. It's much less likely for him to invite an actual Russian spy by mistake even if there are a couple in his contact list, than hackers actively trying to get their way into such channels.

I think most know it's the incompetent mistake of Walz which was inevitable due to the way this administration works, but the OP is questioning their excuses in the alternate reality they are trying to create, somehow their defense makes it worse.