Yeah, I think he did. Ironically, it reads great on mobile -- the text is full width (which on my phone is a great line length) and there's no design getting in the way.
Yeah, I think it would look fine with a max-width style added. I get the allure of lightweight design but it doesn't take much effort to make it easier on the eyes. I know I can override the default styles, but it isn't hard to get right in the first place.