Puncture wounds can be dangerous if not treated properly. A dog's tooth is curved and long, so when they bite another dog it can puncture the skin but also damage the underlying muscle. Even though you might only see a small hole does not mean there isn't more damage under the skin.
My dog was attacked in a scenario exactly like this. He was given Rimadyl to keep the swelling down so the wound stayed open and healed from the inside out. I applied a warm compress twice a day. Physically he healed fine...mentally, not so much.
I think neighborhoods are one of the worst places to walk. In most areas there are not enough regulations or people to enforce them to prevent situations like this. I prefer to walk my dogs in public parks where a leash is required by law...basically stay away from as many idiots as possible.
You will need to do a lot of socialization work once he heals. Put yourself in your dogs "shoes"...imagine your walking in your neighborhood and without warning, someone comes running at you from behind a house and punches you in the face. Would you be scared to walk there again? Scared of people that resemble the attacker? Your dog may show some indicators of fear from this too. I would set up a time to walk in a safe area with someone or a few people that you know that have neutral dogs that can help bring up your dog's confidence.