I know in this country, if I landed with a piece in, say, New York City, I’d immediately rent a car, drive very legally through New Jersey on I-80, and then find a gun dealer in Pennsylvania to send my piece back to a gun dealer at home.
I would NEVER, EVER, tell law enforcement about it, as there are simply too many stories with bad endings.
Now in Taiwan, changing airplanes for another international flight, she might get re-screened in that situation, so things get more interesting there. If I did have possession of the piece in Taiwan it would be a tough call - in all cases, I have to get through Immigration and Customs, so they’re going to get a good look at me (being scared Shiiteless). Another option might be to stash the piece in no-man’s land, perhaps in a bathroom and hope to get out of the country (ideally back in the US) before it’s found, since the serial number will trace it. If not possible, then turn it in.
“Now in Taiwan, changing airplanes for another international flight, she might get re-screened in that situation”
My guess is that is the case, but am not sure.
Still, if this were the case, she had to tell security. And even, if not she had no other choice to inform them because she can’t just leave it in the bathroom, or risk having it found out going through customs or by whatever happenstance.