Yes, I think the dog that attacked the other dog should pay for the damages. I don't think it matters if the dog has NOT had a history with attacking other dogs. Like, lets say Daisy attacked a dog, () and caused the owner vet bills. Should I not be responsible to pay for it? My dog attacked the other dog.
I think it also depends on where it took place, at a dog park where dogs are ALLOWED to be off leash could have a different ruling then lets say a park, where they can't or it is the owners choice to have their dogs offleash.

JMHO.