I have no idea how they managed to crush this packing tube and the Dixon DX004D inside of it. 
My thanks though to Preston at Stoney End Music who has committed to sending me a replacement when they get new stock. You made an unhappy afternoon much less so.
Long ago (about twenty-five years) a guy I know who was a flute broker, representing the works of a variety of makers, took a shipment of something like fifteen flutes from one of them. The postal service delivered it, and the box was flattened with a tire track across it! Every flute was totally destroyed. We speculated about how an earth someone managed to drive a vehicle over the box!
Likely done on purpose as a challenge. Plenty of video of what people like that get up to to make their work more fun.
Though many of us have received and mailed whistles in tubes for quite some time the postal clerk at my local PO really discouraged me from doing it. He said the tubes don’t go smoothly through the speedy automated systems they have and often get crushed. He recommended putting the tube inside a box. My most recent purchase was a nice from the Irish flute store which came well cushioned in a box that was pretty dented. They pack in boxes but cushion the whistle itself with foam or bubble wrap. The last dozen boxes of various things from honey for whistles I’ve gotten through the PO seem to have been crushed in some way but the products inside were packed so they took the shock.
Over the last 25+ years I think I’ve shipped around 4000+ flutes, roughly. In that time I had one flute crushed because I had shipped it in one of those Priority Mail triangle tubes with some bubble wrap around it. Those boxes are not very stout. So I learned my lesson (this was around 2003 or so). Since then, my flutes ship in a heavy-duty cardboard tube (1/8" thick walls with plastic caps) which itself is inside a rectangular cardboard shipping tube. I’ve never had a damaged flute since. Mind you, if someone drove a forklift over it or something similar, all bets are off! But this system really works, especially if the cardboard tube is a bit over-sized, diameter wise. A skinny cardboard tube does not resist crushing as well. So even shipping a single flute, it goes in a 3" diameter heavy tube. I’ve had customers tell me that they have received a flute where the outer box was mangled but the tube inside was intact and the flute was safe. It’s an extra cost to do this–the tube and box together cost about $8 per shipment–but a small price for peace of mind 
Great advice from your postal clerk, wish mine had set me straight. I sent an expensive whistle through the US mail to a buyer in Ireland and the whistle never made it. I’d packaged the whistle in a mailing tube and believe it just never made it through the postal service. I was told it was insured, but come to find out it was not and therefore, I’ve lost a very nice whistle along with the purchase money which has been refunded.
