So,
A talking head for the right cited a fake article and this was noteworthy because? Happens to tons of talking heads and politicians alike - at least he stood up and admitted he made a mistake.
Might not be that simple.
I don't use (anti)social media myself but the way it seems to work is the Big Lie on steroids --- some impoverished kid in Macedonia makes up a story about Hillary Clinton offing a CIA dude, it goes viral, and the mythology has spread ------ would it make one iota of difference if the kid came back the next week and tweeted "I made it up"?
"Once a bell has rung, you cannot unring it".
Now if Inanity made this into a whole segment on his TV show to get the word out that it was a myth in the interest of equal time, you'd have something closer to a balance.