It's fairly simple. In India, he can say anything - he can toe the line of the Indian Govt even if the claim is false. He didn't say anything because Indian defence personnel are forbidden from giving interviews.
I don't doubt that you chaps all believe your nation's version quite earnestly just as I believe mine. So no point going around in circles.
My only point is that if he hadn't shot down an F16, without having information to Indian claims while in Pakistan - he would have in all likelihood told his captors that he didn't shoot one down. And Pakistan would have happily published it to refute India's claims. USSR did that to the American pilot it captured - Gary Powers. It embarrassed America no end which had claimed it was some random weather plane.