In response to the agent’s claim:
“...[A] fact-checker does not make up text. A fact checker receives a text written by someone else, and then determines whether the factual assertions are based on the verifiable truth.
So the question remains: who submitted the text that was insufficiently fact-checked by Ms. Goderich? Who, in other words, first offered the assertion that Barack Obama was born in Kenya?”
SOP would be that the author drafts a bio. This would be a part of the initial book proposal or manuscript draft that was either prepared or edited by the author and/or his/her literary agent. The publisher would then "fact check" only after the book had been acquired and put on the next "list" for publication. These sales handouts, often referred to as BLADS [book layout and design], are prepared by the marketing/publicity departments. They receive headshot and bio information from the book's editor at the publishing house and the resulting handout is precirculated to the book store reps for pre pub orders.
I can tell you from direct experience it would be rare for the marketing/publicity departments to "fact check" a bio that was handed to them by the in-house editor, UNLESS they had no such bio to begin with and they were tasked with writing such a blurb. In that case, they would consult obviously with the author or the author's agent. They wouldn't go looking on Google, for heaven's sake.