I don't condone the placing of the dog in the overhead locker.
However an aircraft is a confined area where food is served.
I do not want to have to eat a meal next to a passenger who has an animal that has defacated under the footwell in the next seat or behind me.
There appears to be issues with snub nosed dogs according to Air France rules.
TRANSPORTING YOUR ANIMAL BY FREIGHT
In certain cases, your pet cannot travel with you in the cabin or in the hold. It must be transported by freight if:
the animal and its container weigh more than 75 kg / 165 lb,
it is traveling to a country that authorizes animal transport only by freight.
Snub-nosed dogs and cats, such as pugs, bulldogs, boxers, Shih Tzus and Persian or Burmese cats, are permitted for transport by freight on flights provided by Air France.
https://www.airfrance.fr/FR/en/commo...maux-avion.htm
Frankly I would be worried about any animal in the cabin that weighed in at 75kg with container.
However back to the issue of the snub nosed animal dying on this flight.
Lufthansa also have this rule.
Information about travelling with snub-nosed dogs and cats
Dogs and cats belonging to snub-nosed breeds have anatomically restricted airways with the accompanying difficulty in breathing. The stress caused by transportation and/or high temperatures at the departure, transfer and destination airports can cause circulatory issues that may result in breathing problems. Your pet could suffer serious health problems or even die during the journey.
https://www.lufthansa.com/us/en/Dangerous-Dogs
Avianca has this rule.
Brachiocephalic Breeds. Some breeds of dogs and cats have a series of anatomical idiosyncrasies that make it difficult for them to breathe properly; the condition is called Brachiocephalic Respiratory Syndrome. These pets have a flat nose and tend to present respiratory problems, making them susceptible to suffering hot flashes and breathing disorders when exposed to extreme temperature changes or stressful situations. Therefore, in order to protect these pets, THE CARRIER prohibits the carriage of the following breeds of dogs and cats or of breeds resulting from crossing them (that is to say, one of the pet’s parents belongs to one of the breeds below):
see
https://www.avianca.com/sv/en/contract-of-carriage.html