OP here! The dog got out when the old man who rents out a room in my friends house - though he'd been repeatedly warned not to - let the dog out. The dogs not very well-trained and does not come when you call him, which is why we keep him inside except for when he goes on walks, on a leash. We had all been getting ready for our schools semi formal so we ran out into the cold in bare feet and dresses while we tried to make sure the dog didn't run away. He was running back towards our friends house when the car hit him. My friend lives beside a public school so the dog was hit in a school crossing zone, so there was no reason for the driver to be going fast enough to not be able to hit the brakes in time, but evidently he was. Fortunately the dog is a massive German Shepard. When he got hit, there was a terrifying bang followed by horrid whimpering. We all thought he was going to die. I'm trained in first aid and checked for injuries on the dogs body, and he seemed fine, except for a scrape on his eyebrow, so I took him back to the house. The bumper of the car was knocked clean off and it seems the dog has a concussion but he will live, but the driver keeps showing up to my friends house, who can't afford a vet bill, let alone the repairs cost.