They didn't trot out the chorus of the defenders of Hiss. Just the immediate kin of Hall and Rosenberg. And then overcame those comments with the last word from those on the inside of the Venona project.
Worth seeing in re-broadcast if you missed it.
That is because the evidence points to the fact that he was a spy under the codename "Garnet". Vasili Mitrokhin's stolen KGB archives also prove so in his book The Sword and the Shield.