I have some issues with this story.
1) He is only isolating (excuse the pun) whey isolate as the form of whey which causes hair loss. What about whey concentrate?
2) I have yet to see any scientific evidence that whey protein can increase testosterone.
3) Why would the isolate raise testosterone but not the concentrate?
4) I went to his website and the "study" which he "published" appears to just be a questionnaire that he gave to his patients on their experience with whey protein isolate.
5) The link you provided included an interview where he cannot pronounce dihydrotestosterone correctly. This does not give me much confidence in this mans ability.
6) This is the kicker! All of this leads to his brand spanking new whey concentrate supplement he is trying to sell to customers which he claims can increase hair growth.
When you come across an article on the internet; it is useful to check the references or try and track down the "research" that the article is referencing. There is a LOT of pseudo scientific writers on the internet and the amount of mis information is mind boggling. An article on somebodies website does not count as scientific research and do not fall for the logical fallacy of an argument from authority:
"I am an expert; therefore my opinion does not need scientific data to back it up."
Fill that shaker with whey my friend. It will do no harm.