No, you understood it wrong. He could just be the conduit for goods and nothing more. It is for the entire Scientific/Engineering establishment in the USSR and its allies to figure that out.

One way might be by simple black-box behaviour testing of gizmo-x received in the USSR vs. the same done in a legal company in the US/Europe/Japan and then narrowing down the problem.

I will bet my bottom dollar that the same thing is going on even today (w.r.t. the usual suspects like China/Iran/etc.) given how crucial Technology has become to maintaining Economic/Military superiority.