Good take on all counts. Neither Waltz nor anyone else running a government agency or a business is doing all their own "group" formations. An assistant f'ed up. It shouldn't happen, but it does. Tighten up operations and move on.
As to Goldberg, he's an a-hole but did nothing wrong here. It's his job to hold the administration accountable. The fact that he would have covered it up if it had been the Biden administration doesn't change that.