You dont want american dollars
You have american life line in your hands in afghanistan
You are a nuclear power state
You dont fear us.
Then why the hell are you acting like minion of united states. If some one is harming your country then why are you giving arguments like uncle sam dont want it so we dont do it
The world is not as neutral as you might think. Basically what the westerners think is the 'truth' for the whole world.
So let's assume for a second that US is not forcing Pakistan to withhold the evidence (I believe they are forcing Pakistan since it would heavily harm their interests and they have done this in the past secretly[though not a secret anymore but was secret at the time]). The evidence must first be told to the whole world.
Now you might remember older times when india used to level accusations against Pakistan and its involvement in Kashmir. Well you know by now that not a whole lot people know about, those who did most likely found about it after 9/11. Because when india used to accuse Pakistan, it wasn't in western interests to deal with that.
Well same will happen with Pakistan. And this is the exact same problem that Pakistan is facing right now that india faced before. Now I have mentioned this before and will mention it again. Several insiders within the army and the ISI have said that they ample proof of indian involvement. It's just that the government isn't doing much about it and they are puzzled as to why that's not happening.
You can make whatever you want to make out of it, but regardless, these arguments cannot be used to disprove indian involvement. It's circumstancial disproving, and more important a very oversimplified view of things. I can tell you with confidence that this world and these sorts of things are not as simple as you're making them to be.