That may be, but the story link posted by the OP doesn't mention pilfering departing passengers or anyone else. Consequently the sentence "Apparently the cruise line had noted a lot of pilfering of items from the ships, presumably by departing passengers," sounds as though the OP thought a passenger may have pilfered the list.

In any event, I suppose it is also possible the list was simply dropped by accident by an individual authorized to have it. Either way, it was an unfortunate thing to have happened, and doesn't say much for Cunard's security measures.