How he decided on derm? Without any experience, I would say lifestyle and money. That's strike 1.
No derm letter? That's strike 2. Especially for such a small, connected field like derm. Students at my school are encouraged to use ONLY derm letters when applying.
And finally the stats. I have a "friend" myself with a higher board score, uncertain AOA status, solid but not extraordinary scores, and heavily focused derm research. This "friend" was still urged not to apply. With your "friend"'s mediocre stats, that's strike 3.