I'm going to play devils advocate a little here, so please bear that in mind as you read on!!
You say, or imply rather, that dogs make you nervous, was this dog attacking you or greeting you?
I have dogs of my own so I'm very comfortable with them, I've had dogs come up to me and wrap there jaws around my arm, but they are not attacking me, they are greeting me and being realy friendly, tails wagging and walking me to the door.
Ditto small dogs that hold onto your trouser leg and do the same thing.
If you yank your arm away from some big dog then you can end out hurting yourself (rather than the dog hurting you) or tearing your trouser leg if you pull your leg away in a panic thinking that you are being attacked.
Ok, I know that from what you say, it sounds like the dog came out snarling and nasty and actually leapt up at you and sank his teeth into your coat, but it also needs pointing out that if someone is terrified of dogs, some dog coming over and barking in happy greeting, or just barking because the door has been knocked, because of their fear of dogs, what they see and hear can be missinterpreted.
Mind you, if that dog actually damaged your coat, you shouldn't have left before getting the owner to agree to compensate you for the damage, proving it afterwards won't be easy.
And if the dog was attacking you, you should have reported it straight away.
I'd have told the guy straight away i was going to report him too.
Ian