How can you say so, when Pakistan said that it would investigate if India shared information and cooperated, and it investigated when India shared information and cooperated (to a small degree)?
Pakistan isn't to blame for India's slow response in providing the dossier.
Now if Pakistan had said that it would not investigate, would not cooperate, and India had in fact shared evidence earlier, then I could see your point about Pakistan 'forced by international pressure'. But in this case Pakistan said from the get go what it would do, and followed up on those statements.
This whole 'international pressure thing' is IMO a continued demonization of Pakistan in India, to continue to spread dislike and hate against it, because it aims to undercut Pakistan's cooperation and actions by painting them as having been taken only under 'international pressure', despite evidence to the contrary, as I pointed out.