While the writer is wrong, the post itself is actually quite interesting and made me think more about epistemic luck. I think Zack does correctly point out cases where I would say rationalists got epistemically lucky, although his views on the matter seem entirely different. I think this quote is a good microcosm of this post:
The Times's insinuation that Scott Alexander is a racist like Charles Murray seems like a "Gettier attack": the charge is essentially correct, even though the evidence used to prosecute the charge before a jury of distracted New York Times readers is completely bogus.
A "Gettier attack" is a very interesting concept I will keep in my back pocket, but he clearly doesn't know what a Gettier problem is. With a Gettier case a belief is both true and justified, but still not knowledge because the usually solid justification fails unexpectedly. The classic example is looking at your watch and seeing it's 7:00, believing it's 7:00, and it actually is 7:00, but it isn't knowledge because the usually solid justification of "my watch tells the time" failed unexpectedly when your watch broke when it reached 7:00 the last time and has been stuck on 7:00 ever since. You got epistemically lucky.
So while this isn't a "Gettier attack" Zack did get at least a partial dose of epistemic luck. He believes it isn't justified and therefore a Gettier attack, but in fact, you need justification for a Gettier attack, and it is justified, so he got some epistemic luck writing about epistemic luck. This is what a good chunk of this post feels like.