To be clear, I'm not saying that person was wrong to criticize the other post necessarily. I just think it's a testament to the abilities of GPT-3 that it could fool a reasonable person.

That would be true if it had actually happened, but it didn't. What happened is that someone faked it to exploit people's desire for such a thing to happen, and then used the claim to get a lot of attention, including getting some journalists to write about it—whether because they actually believed it, or simply because it was such an attention-getter.