if it was marked and he declared it or was not given the opportunity to declare it it would have lost the easy charge of transporting 10k into or out of the country..I would assume they questioned him then again they could just lie about it...
My guess they were NOT going to give him the opportunity to declare it. If he had been offered a paper document or a digital one, it would have gotten “lost,” and they would have had their entrapment. So glad Pop was smarter than they thought.