This is a very good post...some wonderful responses as well. I too have yet have had a puppy returned to me. With the exception of a mini pin pup that I was told bite their daughter. That is a long story and won't go into details on that. I welcomed the pup back. After spending another month with me I found a more suitable home for this puppy as it had been though a lot from the daughter of the old owners..Until a house fire took this little girl, years later from her second owners, she had been the best mini pin they had, per their conversations with me.
Since I haven't had any problems with my puppies all I can say is I would take each case one by one. As many bad breeders that are out there, there is as many bad pet owners too. Although we screen our new potential owners for our puppies, this is never a total guarantee for us either.
I will stand by my puppies and if anything is found that was missed by my vet, these findings would have to be given to both my vet and I. The right and proper measurements would be taken, so both the pet owner and I happy with the outcome. MOST IMPORTANT ISSUE WOULD BE IS THAT PUPPY WOULD GET THE MEDICAL ATTENTION NEEDED. I would be willing to cover that cost up to the amount of purchase of the pup, with written documentation from their vet to be given to my vet to review the findings.