It seems to me like there may indeed be a lawsuit against Delta or at least some kind of settlement will be sought:
"Massey [the victim's attorney] said his legal team is currently seeking information from Delta Air Lines regarding their compliance with policies for unrestrained larger animals within a plane's cabin. He also wants to see the verification process of their emotional support animal training requirements.
"It is troubling that an airline would allow a dog of such substantial size to ride in a passenger's lap without a muzzle," said Massey. "Especially considering the dog and its owner were assigned a middle seat despite Delta Air Lines' policies that call for the re-accommodation of larger animals."
At this time, a lawsuit has not been filed."
I'm not a lawyer, but I'm guessing the victim will indeed get paid. The lawyer is seeking information on policies and procedures. He just needs to poke one hole in those to get his case. Also, this is the first mention I've seen of using a muzzle, and I've wondered about that. I have a muzzle for my dog. He was raised wearing one, as a former racing dog, but I've only actually used it in a couple times. A neighborhood friend of my daughter's wanted to "meet" him, but was a little scared. We initially kept the muzzle on him with us holding him whenever she was at the house, but now she happily plays with him without the muzzle.
This is the source of the quote I referenced. Warning: it has some pictures of the victim's wounds that some may find pretty gross and possibly disturbing.
http://www.al.com/news/mobile/index.ssf/2017/06/marlin_jackson_support_dog_bit.html