Something very similar happened to my chickens back in April- Neighbor's dog got after my hens on my property. My neighbor never came by to check on what had happened (he knew that his dog was over at my place and KNEW that I free range my chickens). After penning up the ladies, I drove over to his house and handed his dog to him- I told him to make no mistake, that the next time he heard a gun shot from my property, he may as well throw his dog food away because he wouldn't be needing it any longer. He got a little upset ("you shouldn't free range your chickens etc"). Needless to say, he took me at my word because his dog is now in a kennel with a top on it and hardware cloth buried around it.
Hope your chicken calms down and comes back to the coop soon -
Hope your chicken calms down and comes back to the coop soon -