Upvote:4
Everything is possible (although not that likely):
Customs certainly has the authority to do so. I always had the impression that, in general, they cared very little about what goes out of a country but there are things that are export-restricted (depending on the country of course): arts and antiquities, military technology (and that includes software, documents and parts, not only a full weapon systemβ¦), undeclared cash, protected animals and obviously everything that's flat-out banned like illegal drugs or forgeries.
It's possible as well, it's much less common than delays or outright losses but I have heard about a few cases of wildly misplaced luggage (admittedly a few decades ago, I don't know if it's less likely today).
Upvote:4
Yes, Customs can do pretty much anything they want, but, it sounds like someone is mis-reading what's in the PNR because LGA does not have Customs or any FIS.
If there was a reason to hold the bag, that would have happened at DTW.
So, as suggested above, the airline mis-handled the bag if it indeed end up at LGA. There, it's possible someone mis-read the tag thinking it came in from AUH.
This isn't common but it happens. It's good they know where the bag is so really all you can do is wait.