The way I discriminate between a false master and a true master, is that I listen to the response I get from my body and being. If my body and higher self resonates with the teachings, I accept it and believe it to be true. If it doesn´t, and leaves me with a feeling of scepticism and distrust, I reject it.
So I "simply" sense with my intuition and reason with my higher self, what is true and what is false. I have trust and faith that if a false master or teaching is trying to "seduce" me, life - or God - will intervene, because that has happend so many times when I have been on the wrong track before.

Jenny