I'm so so sorry that this happened to Banksy. Was the breeder the trainer? I'm confused on that. While it won't bring Banksy back, you may want to take your breeder up on the offer? Breeders may or may not be attached to their pups but for most I imagine they're puppies they never get attached too. Gosh I'm really sorry this happened.
PS.....YOU DID NOT FAIL!!!