I am sure your dog was loyal and well behaved for you on or off leash. It used to be that a person could have his dog join him on a walk if the dog was well behaved and listened loyally.

The reason a leash law became law was more about dog owners that did not have well trained safe dogs but instead had dogs that if not leashed could be dangerous in some way.

It’s unfortunate that your neighbor owned a dog that could cause harm and did harm your kind loving dog. As with all laws the down side can be that even though your dog was nice and well behaved and did not deserve to be attacked, you did not have it on a leash so the good dog in the story did not get justice and respect for being a good dog

Also, even if your dog was on a leash it probably still been attacked by your neighbors dog. The other thing I see is that your neighbor must not have had his dog contained on his property so it could not cross a boundary and attack like that.

What would have been just is that your neighbor should have paid half the expense his dog caused to your dog and admitted his failing to contain his dog. Actually, his homeowners insurance should have paid for the damages his dog caused.

Insurance companies now will not insure your home if you have a certain breed known to be dangerous. Some companies put in a clause stating they will not cover any liability for a home owners dogs.

It’s good that you channeled your anger into positives for yourself. Anger is an emotion that fills the body with adrenaline meant for “fight”. At least you found a productive way of burning off that adrenaline.

Unfortunately, when you see or are near where your dog was hurt you get triggered. Unfortunately this is part of our human design meant for our survival. Added to that your neighbor doing nothing in terms of repairing trust by admitting his failings. It sounds like he is a coward who lacks the charector to repair.