Yes, there are two big giveaways in the article. The first is how the word LaTeX is typeset. This has a command that produces a much fancier typesetting in most LaTeX documents. The second big giveaway is a bit deeper into the paper
> It turns out there is an alternative that satisfies my economist mindset—FaKe LaTeX documents created in Microsoft Word. That is exactly how I produced this note.
Well he did cite a study showing that people were more productive using Word than LaTeX. That's a very good justification assuming it's factually accurate and the productivity gap is meaningful.
Most of his complaints about how hard it is to use LaTeX seem absurd, but that doesn't mean he isn't experiencing them or that they aren't common among less technical users.
> It turns out there is an alternative that satisfies my economist mindset—FaKe LaTeX documents created in Microsoft Word. That is exactly how I produced this note.