It is a fluke because as noted, you cannot be a winner if a dog dies, therefore it is in the interest of the race to make sure the dogs get top notch treatment.
The guy took his dog to the vet, it is not as if he neglected it. Now, being a rookie, he may have not been as tuned in to his dogs as he will be once he gains experience, and he may have missed a sign that the dog was in distress because dogs hide their issues, particularly when in pack, and in the excitement which all working dogs feel when they get to do their work, there may not have been any visible signs of trouble until later after the excitement died down and the dogs were unharnessed and the racing frenzy was over.
Thanks for being another voice of logic in this conversation. It’s amazing how emotional people get when animals are concerned.