Sometimes if I brought a friend to class he would treat that friend with the most respect, talking to them, telling them how great they were and calling them by their name? There were may other tests through my 10 years and several times a week study with him.
I never asked him for proof I had to learn to trust my own intuition and verify within. My practice was based on doing what he told me to do, practice, research and verify within then ask questions and if he felt I had done my work he would answer in a way I could understand by either showing me. I had to earn my way through love and respect of him and his tradition.
We want everything so easy, we all want to know it all, we can even pay for a certificate today a month or two one is a teacher. With the real and true there is nothing easy about it or there is no short path.
I see people charging astronomical fees to learn Yoga and Tantra, do they ever give anything back to the people of India is their really any love and respect towards the people who preserved these traditions through their own culture and lineages.
It is Kali Yuga what is real is seen as unreal and what is unreal is seen as real.
I had a Jyotish teacher who always let Indian people take his classes for free, why because it did not belong to him he knew and acknowledged in humility that Yoga, Jyotish, Tantra was a gift given to him and that it was not his ancestors who brought these subjects through today, it was not his ancestors who gave up their life after life to preserve their tradition. He understood that these traditions had been passed down for thousands of years through family lineages. He understood what a gift it was for us to have a drop.
It is a gift that we even have the grace to pass anything on or teach and the biggest thing one can do is give respect and give back.