You’re shocked to hear that girls are treated differently by mentors? Or you’re shocked to hear that someone assumed he does because he’s a man? If it’s the former, then I don’t know what to tell you, because it absolutely does happen. If it’s the latter, then I think you misunderstand what I’m saying, and the question that OP asked. I understood him to be asking if there’s inherent bias because he’s a man and if he should step aside for a woman leader. Which is not what I advised him to do. All volunteers are great, my advice was to be wary of certain situations that would be better served by someone who has lived their life as a woman, who would understand the nuances.