There is no reason for the book author to be biased. We don't know if he is biased or not. However, we know for certain that Jeff Bezos's wife is very biased. S

There is no reason for the book author to be biased. We don't know if he is biased or not. However, we know for certain that Jeff Bezos's wife is very biased. She has a horse in this race, so to speak. So whatever she says is probably to protect Jeff Bezos's reputation, not to uncover the truth.