I have never heard such language and denail they said. They must have been running with it when it was younger etc etc. I cannot repeat what he said to me but it was awful. With this abuse I started to say, they could legally contact trading standards as the dog was unfit and they could sue them. He then said he was going to find out where we both live and come and smash my face in. Amongst lots of other Enough said Louise your not dealing with a decent breeder here, is it worth the aggro, really is it? It's not your dog, not your problem and these people did not go after the breeder for 14 months or until the pup died. Unless they wish to go through the process of taking things to court and being threatend is it really worth it.
Trading standards may well look into things with the Dam dead, from what? There may even be a case here, the police may well even take out an injunction and you could go to court about the threatening behaviour, you have cause here for all these things, but I ask again, is it all worth it?
Personally I would walk away, who wants to get involved in a big mess like this, they had the dog for 14 months, they would need to prove the pup was just not just 'unlucky' court cases like this take months, maybe even longer depending on other cases.
I would tell them to put it down to experience, next time they may well learn to get a dog from a good, referred breeder, but they need to fight their own battles if they wish to pursue I would step away now Louise.