yes, i've seen videos like that too, infact i've had personal experience seeing deer keep breathing after being shot in both lungs. that's my exact point.

This is how it works:

When a bullet hits the lungs while an animal is exhaling, all of the oxygen is being let out of the lungs. as the bullet passes through the lungs, it prevents the animal from inhaling anymore oxygen and causes the animal to instantly pass out. This is not an instant kill, it prevents the animal from suffering for one thing and it also prevents an animal from running after the hit. just because an animal is breathing doesn't mean it's not down for the count. i realize that it takes a lot of patience to be able to wait for the animal to exhale. and as far as "making sure" that you get a good shot, isn't this really the best way??? i think that any form of patience in harvesting an animal is a good thing.