[DCBryan1]

I want to know how the crew discovered it in London. I’m guessing it was in a sealed container, so how would they know?

Depending on the radiological isotope, a pilot could have touched the metal device and "burned" him radiologically, only to become violently ill within a couple of hours, unexpectedly. Sure sign of severe >500 rad exposure (2-6 Grey?).

[Rutles4Ever]

What metal container? What if it was in a cardboard box, like most shipments? How would anyone know to look in “that box over there” because it looks suspicious?

There’s something missing here; because if there’s no radiological device, then it really makes no sense, as I can’t imagine any reason to just presume there’s an altered ink toner cartridge in some random box from Yemen.