Indian Members don't know about the writer of article, that's why they are terming the article as rubbish, here is the short info on writer
Tariq Ismail Sagir is ex-ISI senior civilian agent cum writer and journalist. He has spent time indian jails in early 80's as he was caught in india and later he was swapped and got released in this way. Since then he has written lot of books about Espionage and Counter-Intelligence matters.
The Main Thing in the article is that, The writer said, " On Special Request of mine, I was granted access to interview this Particular enemy of the state"
About why Pakistan didn't make hue and cry on this matter because, This particular Person is of Afghan nationality, We don't have direct evidence to implicate Indian in this matter, all we got is indirect references and sources.
That's why Pakistan is in weak position and don't implicate Indian in every matter because they always use third party to carry on their agenda i.e afgan nationals or our on brethren. All they do is, they provide training and materials to individuals and these things can not be counted as evidences as India can easily say, they have smuggled the arms or there are vast area of land where they can do training.
In Short Individual confessions doesn't count as hard evidences unfortunately, it only gives idea who is doing what and that's why we are also implying indirect methods to cut off the indian influence in Afghanistan