Rescued Hen from Dog (but it died anyway)

Today I was washing dishes and I looked out and saw the neighbors "junkyard" dog in my back property.  He was mauling something, but I couldn't figure out what at the distance I was.  I thought maybe he pulled something out of my compost bin or something.  Then I saw what looked like feathers and I sprung into action.  I ran out yelling like a crazy person - scared the crap out of the dog I imagine because he dropped what he was mangling and took off about 20 feet then turned to look who was screeching like that.  

What the dog had was a hen (Rhode Island Red), and she was laying like she was very injured.  I picked her up and he head was floppy.  I walked her into the house; she was breathing.  I put on my shoes and wrapped her in a towel - and I began walking to the neighbors (two properties over where the bird must live as I see chickens scratching there a lot).

On the way the bird stopped breathing and died.  I told the neighbors what happened, and they commented that they were wondering what happened to some of their birds.  I told them I'd never seen one of their chickens on my property before.  They were very nice, and I left with a carton full of fresh eggs and a half a bag of peaches (score!).  I promised I'd drop by and bring some stuff from my garden.

Once I got home I headed right for the back property to see if I could see how the dog got in and where he attacked the bird at first (figured there'd be feathers).  I found three more hens scratching around where my compost piles are.  I shoo'd them to go back over the fence, but they just scooted away from me and kept up their scratching.  

I left them to their business.  I figure they'll return home when the sun goes down.