Proper etiquette on selling pups means they are guaranteed to be healthy when they leave your yard. No pup is guaranteed to hunt no matter how good the bloodlines are. Every dog you buy is a gamble. Sounds like the buyer is new to the hog dog game or is just a dick
You can guarantee the health of a pup leaving your yard but guaranteeing that a hunting pup wont die in a 6 month period is to be the responsibility of the pups owner, not breeder. A breeder can guarantee a pups health for how ever long they want, but 6 months is a long time. To me.