The AP reported that publishers rarely fact-check books, citing time and expense.
1) That the book was so bad , too obvious?
or
2) That there still is some leadership in the publishing industry and we should be encouraged.
https://en.wikipedia.org/wiki/Houghton_Mifflin_Harcourt
Houghton Mifflin Harcourt, the books publisher in the U.S., told the New York Times called the issue an unfortunate error, but said that the the overall thesis of the book Outrages still holds.