Hi sorry to hear about your friend
One thing your friend must do immediately is stop doing all the practice and throw out all the materials which might be there from Isha organisation.. if he goes to Isha teacher to discuss this they will say keep doing your practices nothing to worry you might be doing it wrong come for correction don't go there otherwise his life could become hell..if you go there you will find so many Happy people he won't be able to believe whatever is going through it is because of Isha yoga...
In one sense he is very lucky that you came across this forum so easily and so early you will not find too many negative press about satguru and isha organisation. but it is a cult very very subtly they brainwash people.
He is accused of killing his wife none other than his father in law but you won't find too much about that on internet...
This link might help him open his eyes if he is not too much impressed by him..
Didi got initiated by jaggi vasudev himself?
Hope it helps and all the best
