It’s hard to know what to do here. They are middle school bullies, and everyone knows that you shouldn’t give them the satisfaction of a response. Having been bullied though, I know that is easier said than done.
I think its good for reporters to do this sort of segment every once in a while, you have to remember that Trump Jr. et. al. succeeded in diverting the public’s attention from other things for another 10 minutes. And it doesn’t move the needle - it won’t convince anyone who is a Trump supporter that uh, maybe they shouldn’t support the worst family on earth. As @beschizza said,
They being the 40% or so of people who are supporting Trump through thick and thin.
If I were Anderson Cooper and CNN’s investigative team, I am digging into Trump’s family as much as I can, following the money and the paper trails as best as I can. Although being vengeful is probably against journalistic ethics, maybe that doesn’t matter if your reporting is truthful.