It's likely more dangerous driving a chin across the country than flying it to another country. Do you really think someone spending thousands of dollars on a chinchilla wouldn't want the animal delivered safely ? Furthermore do you think that one of the most knowledgeable if not the most knowledgeable chinchilla breeders in the world wouldn't have the foresight to take the proper precautions and develop a process for safely shipping animals overseas, especially since they are being sold for thousands of dollars? It's just bad business to ship dead multi-thousand dollar chinchillas to Europe and China.
Chinchillas can certainly die from stress factors, but since these aren't, perhaps the amount of stress everyone is speculating about is actually being exaggerated.