Irfan saab,
I have heard this theft narrative quite a few times. The aspersion being "ohh look India is no better, there security is so lax that their material is getting stolen from nuclear installation, and then suddenly rhetoric steps up gears and it becomes fissile material getting stolen, and then the narrative changes to nuclear bomb and then finally somehow India becomes a proliferating agent.
Let me make a categorical differentiation here, lapse of security causing theft of unprocessed ore, or Beryllium in no universe equates to institutional proliferation of reactor plans, enrichment protocols, and entire centrifuges done by Pakistani scientists (which he himself claims was under the patronage of the government, also evident from his punitive sentence). I appreciate the clever wordplay which I would have too used if I was in your position, but theft of ancillary material related to nuclear installations and a well crafted Nuclear proliferation as a quid pro quo to states like NoKo, Libya etc are completely different regimes. Light rhetoric might distort it to make a good argument, but if you a dive a little bit into specifics and the differentiation is not as murky as you would like it to be.