"An author might know nothing about writing, which is why he hired a ghost. But he may also have the literary self-confidence of Saul Bellow..."

"... and good luck telling Saul Bellow that he absolutely may not describe an interesting bowel movement he experienced years ago, as I once had to tell an author. So fight like crazy, I say, but always remember that if push comes to shove no one will have your back. Within the text and without, no one wants to hear from the dumb ghostwriter. I try not to sound didactic. A lot of what I’ve read about ghostwriting, much of it from accomplished ghostwriters, doesn’t square with my experience. Recording the author? Terrible idea—it makes many authors feel as if they’re being deposed. Dressing like the author? It’s a memoir, not a masquerade party. The ghostwriter for Julian Assange wrote twenty-five thousand words about his methodology, and it sounded to me like Elon Musk on mushrooms—on Mars. That same ghost, however, published a review of 'Spare' describing Harry as 'off his royal tits' and me as going 'all Sartre or Faulkner,' so what do I know? Who am I to offer rules?"

 
From "Notes from Prince Harry’s Ghostwriter Collaborating on his memoir, 'Spare,' meant spending hours together on Zoom, meeting his inner circle, and gaining a new perspective on the tabloids" by J. R. Moehringer (The New Yorker).

It occurs to me that another reason not to record "the author" is that you don't need verbatim quotes. You are also the author, and the whole idea is to put it in your words as if those were the author's words. So not remembering the author's words is an advantage. Those inadequate words are lost, but you have notes on the stories, and then, to write the memoir, you must reconstruct the account and you will, naturally, use your own superior form of expression.