What a distressing story! Every rescue I’ve dealt with has the policy of returning the dog if theres a problem. One of my girls was returned allegedly for snapping at small children, she was two yrs at that time, she’s been with me five years and has never shown even a hint of aggression of any kind. What she does do is give a snarly bark at the other dogs if they go near her food dish, but even then, she has never snapped. She has been perfectly safe with my little granddaughter since she was a baby. I suspect the previous adopters just found it too much to look after a dog as well as their young children, and used any excuse. But at least they did the right thing and returned her, so she has had many happy years of mischief and fun that this poor dog has been denied. I hope these people are prevented from ever getting another dog, but sadly, greyhounds, and other dogs, are just too easy to come by, due to the lack of control on the supply chain and consequent over-breeding.