Author here. That's a fair point. Interviews will never be fully two-way. The intent of the point is to allow them to correct misunderstanding I as the interviewer may have (making it slightly better than me going away with an incorrect interpretation). Interestingly quite often candidates will give me feedback on the interview process as well.
But you are right. Interviews will never be fully equal.
But you are right. Interviews will never be fully equal.