I think there are a lot of good opinions here as well as some rather harsh ones that are only good in a few circumstances.
First off, Kato, I'm sorry to hear about your dog, I know how bad that feels. I lost my Sammy to poison my neighbor set out for coyotes. My neighbor raised fighting cocks (I didn't condone that) and my dog never bothered them. But when he found something sweet along the fence, he gobbled that up. He died in my arms and I had to bury him with my father's help. I was only 13 years old.
I had another dog, Shadow. She had a lot of promise. But she went missing one day, we think snatched from our front yard. Nearly a year later, we found her, and she came back with a mess of problems. With this was chicken killing. After a few months, we did the responsible thing: we put her down because she was killing neighbors livestock. A dog's behavior has ALOT to do with how it was raised!
The neighbor on the other side of us had a rottie that got loose and ripped up two of our goats, a milker and a show goat. We didn't shoot him, we allowed the neighbor to put him in a better pen. If he had attacked again, we would have shot on site of him on our property.
Dogs wander, they just do. My dogs take themselves for "walks" from time to time, and it takes us a bit to find them. But usually they keep to the roadside.
I think some people need to give dogs a little bit more consideration before they pull the trigger. I understand that a wandering dog can do sever damage to a herd, I have raised orphans of such attacks.
BUT, I think you should THINK FIRST, SHOOT SECOND. You can always decide later that you should shoot a dog, but you can't ever bring it back to life.
I think the neighbor in this instance is responsible since he did not notify the other property owners he was going to set out traps, and also it was under his permission that the traps were set out on the wrong property. Also, he is responsible for the impact on the environment that he is making by allowing for a population explosion and for inhibiting nature from trying to balance it out.
There are reasons for "Laws of Nature" just like there are laws for which we govern ourselves. What will become of this population should something happen to this man? They will move to the next available farm and try to live off their resources. If they move into the wilderness, a large concentrated herd of that size can easily strip an area of it's natural resources, causing not only problems for them, but for any other creature that may co-depend on the same materials.
Near where my parents live there is a high-end resort/residential area that has had a problem with deer. It is illegal to hunt deer there, and many people feed them. What has resulted is a rising number of severe car crashes, many fatal- where a person has either struck a deer or crashed from trying to avoid hitting a deer.
How can my 'essay' be boiled down?
"Everyone is responsible for their actions-whether malicious or not- and the outcome. If something you are doing has been pointed out as in error, be a wise enough person to change your way!"