I think it just shifted from your situation, to one person's advice to rehome an animal-killing dog to a city home, and another person saying that is irresponsible because the dog might become a child-killing dog in any environment (cities have children too.) I won't make any bets about how long people can argue about THAT subject!
As regards your own dog, it sounds to me like you have things pretty well arranged. The dog and the chickens have good separate lives, because of a fence. Yes, a chicken got over the fence one time and got killed, but plenty of other people have chickens get over a fence and killed by coyotes or other predators. Your dog is not a threat to anyone else's livestock or children, because your dog is not running around unsupervised. It just doesn't sound like a big deal to me