Interesting read. I wonder whether this was an attempt at social engineering†? While we tend to think of the NSA (or other foreign agencies in this field) working on intercepting information only through electronic means, sometimes a direct approach is often easier (obligatory - xkcd: https://xkcd.com/538/).

Perhaps all they wanted was the source code of his application to repackage (after introducing a backdoor) and distribute it on the internet or directly to targets of interest ... perhaps it was part of his training ...

†Social Engineering (https://en.wikipedia.org/wiki/Social_engineering_(security)) in the context of information security, is the psychological manipulation of people into performing actions or divulging confidential information.