In case you failed to notice, the lambda calculus example is actually a Scheme program, which means that, drumroll please, it is source code AND mathematics (Scheme is an interpreter of an extended lambda calculus).
If you were trying to sound smart it didn't work, until you change your apparent position that it is wise to give technology to your enemies for free most actually intelligent people will question your sanity.
Another thing that he utterly failed to notice was the complete and abject failure of ITAR restrictions to essentially ban an entire area of what is essentially mathematics from export.
ITAR was abhorrent to everything freedom-loving Americans
hold dear. Prior restraint of abstract ideas. No wonder he supports it.