Not stupid, but definitely naive.
It doesn't even need to be a careless baggage handler. I don't know if baggage handling machinery has improved lately but that occasionally used to mash things up as well.
I live near Heathrow (London) Airport. So much baggage used be stolen the locals called it 'Thief-row'.
The best joke was the British Airways advert for Concorde. "Breakfast in London - lunch in New York" to which was added, luggage in Dusseldorf'