That jumped out to me as well, particularly given the otherwise high quality of the writing. It's an example of what I perceive as a more general phenomenon - spelling errors, particularly confusion of uncommon homonyms[note], appear to have increased in frequency. I previously attributed it to the internet simply lowering the bar for "publishing" to the less educated, and the greater proportion of text that makes it to our eyeballs without the intercession of an editor - but seeing such a glaring mistake in a text clearly written by someone with otherwise very good command of the language makes me wonder if there are other factors, perhaps the rise of verbal media such as audiobooks, podcasts, and YouTube channels.
[note: I see "fazed" spelled as "phased" more often than I see it spelled correctly now. I suspect its proper spelling will eventually die out.]
[note: I see "fazed" spelled as "phased" more often than I see it spelled correctly now. I suspect its proper spelling will eventually die out.]