Welcome to the Forum...
This is another case of proving the proverb "Silence is golden"... or as my ol' fishin' buddy sez, "Even a fish wouldn't get in trouble if he kept his mouth shut!"
Too bad you ADMITTED you shot the dog.
The burden-of-proof WAS on the dog-owner. He would have had to PROVE you did the shooting, even in a civil suit... and proving it would have amounted to an IMPOSSIBLE job since he didn't see you do the shooting, the dog can't talk and the bullet is long-gone and couldn't be found to prove it came out of YOUR rifle.
Unfortunately, at this point, there is no doubt about WHO shot the dog.
However, even though you admitted you did the shooting, it still seems that you were within your rights to shoot a "vicious dog that gave all the indications that it was preparing to attack you."
If you swear, under oath, that the dog made a direct "bee-line" for you, a 2nd. time after it KNEW you were there, and that upon seeing the dog coming, you were in DREAD FEAR for your safety, courts put greater emphasis on "human safety" than on "animal safety".
Net result... the dog loses.
But the advice to contact the insurance company that carries your home-owners policy (if you don't have an "umbrella liability policy") is a good one.
They will ask a lot of questions. However, the insurance company does NOT need the dog owner's name in order to tell you whether or not your policy "covers" you in this situation.
I would not give the insurance company the dog-owner's name in this case since you are not sure what the dog's owner intends to do. You don't want your insurance company "stirring up" a law-suit by contacting the dog-owner and/or making him realize he might be dealing with the "deep pockets" of an insurance company rather than the lean pockets of a fellow hunter.
"Greed" does strange things, even to SEEMINGLY decent men.
The dog-owner may drop further action... or he may initate action at a later date (the statute of limitations is probably 3 years or less). If you determine your home-owners policy "covers" you, then I'd suggest you simply sit back and wait... secure in the knowledge your insurance company will defend you up to the limits of the liability amount on your home-owners insurance policy if the dog-owner successfully brings suit against you.
Meanwhile, do NOT change insurance companies. Insurance companies tend to more vigorously defend CURRENT policy holders as opposed to PREVIOUS policy holders.
'Nuff said... good luck. :-)
Strength & Honor...
Ron T.