Sorry you had to go through this. As an animal lover, it is particularly hard, because you don't want to hit a dog, so it is heartbreaking and frustrating!
Accidents happen, I have had dogs get loose, but I am usually hot on their heels and after them! Once though, a friend came over, it was dark, surprised me, I went to answer the door, didn't turn on the lights, because I just wanted to peek out and see who it was, well, once I saw it was her, I opened it up and let her in, then turned on the lights. My dogs were all barking, etc. We went in the living room, they quieted down. After she left, I was looking around and realized I was missing a dog! I had 5 dogs at the time and one had snuck out when I had let her in and I had never even seen it! I panicked and everyone immediately got their shoes on, flashlights and out we went.
I hate when people know their dog is loose and DON'T CARE! My one neighbor has a large pit mix, the owner is good, takes him out and watches him, walks him every night. The granddaughter (18) just lets him out and then off he goes, running the neighborhood. They have told me before he likes to chase the birds in the field, oh great, so I am worried he will notice my chickens, ducks and geese! He is a great big baby, totally harmless to people, but I wouldn't trust him with my animals. Last week he came running into our front yard, luckily my husband saw him and went out and called him before he got around to the other side where the animals are. He came running and rolled onto his belly, and Dh walked him back home. Then yesterday a pickup pulled in with him in the back and asked if we knew where he belonged because they found him running in the road. If something happens to this dog, both the owner and granddaughter will be heartbroken, but the granddaughter needs to become more responsible and realize if something happens it is HER fault!