Tl;dr: Early This Morning A Neighbor's Dog Was Uncontrollable On The Leash, Pushed Under The Chain Linked Fence To Attack My Dog On My Property. My Dog Has No Injuries, But The Other Dog Is Severely Injured. Neighbors Ignored Their Dogs' Injuries All Day

There has been no legal action as of yet, but both my neighbor and I are severely scared that the vet at the emergency clinic will force us to contact animal control and start legal action against each other. I would like to seek legal advice in case it has to come down to it and if there is anything I should do to prepare. I live in the state of South Carolina. I am the main caregiver for my dog Bipsy. She is a 90 lb mastiff brindle mix. She commonly shows aggression towards dogs that are similar in size to her. However, I have always controlled her and never had an incident until now. The other dog, Sasha, is a white 100 lb pitbull. This story has been recounted by my grandmother and the neighbor. I was not present during the situation. I was at work. This morning around 7:30 AM, while I was at work, my grandmother opened the front door to let the dogs out to potty. We have a chain link fence so we do not tether our dogs or leash them. Our neighbor, the mother of Sasha’s owner, who is also the same age as my grandmother, was walking Sasha on a leash in front of my house. My dog Bipsy saw Sasha through the swinging glass door after the main door was opened. Bipsy forced through the glass door and ran up to the fence line to bark at Sasha. This is the usual response for Bipsy when she sees Sasha. Usually, Sasha is tethered to the side of the neighbor's yard, but we try to take them out at separate times. Sasha started dragging our neighbor to my fence line. Both dogs were acting aggressive at this point. Sasha pushed underneath the chain link fence to attack my dog Bipsy. (The chain link fence is dented inwards now. I have taken photos.) After Sasha pushed herself under the fence, Bipsy started biting at Sasha and severely wounded her. My grandmother said that it took 5 minutes to separate the two dogs, and another neighbor had to help separate the two. (I do not know this neighbor and did not get his input on the story yet.) My grandmother contacted me as soon as the incident was over, and I left work at 8:00 AM, stopped by a store, and grabbed medical items that are safe for dogs. As soon as I arrived home, I checked Bipsy for any puncture wounds, bites, or scrapes. I checked her entire body and found nothing. My dog is not injured at all. I asked the neighbor if she wanted me to tend to Sasha’s wounds if she was still bleeding. The neighbor said that everything was okay. She contacted her son and they washed the blood off of Sasha, and used “peroxide” to rinse out their dog wounds. I commented that peroxide is not good to use on wounds in general but trusted her words that her dog was fine. I told our neighbor that we need to set up a schedule where both dogs are not out at the same time to make sure this would never happen again. I talked with my grandmother on ways we can help better control Bipsy so this would never happen again (wearing a harness outside, making sure the glass door is secured shut, and practicing recalling with Bipsy, since she only listens to me at the moment.) I was tired from work so I tried my best to sleep. My grandmother woke me up at 4:30 PM, and the neighbor was at the door and asked me to come over and look at Sasha. I came over, and her owner, the son, was there. Sasha was laying on a bed, shaking and not moving much. He pointed out a deep puncture wound behind her front leg that was oozing blood still. I was very concerned because the attack happened 9 hours ago, and the wound was still bleeding. I said no wound should be bleeding for that long, and Sasha needed to go to the vet hours ago. He claimed that they did not notice that wound until then. I asked why it took so long to get over to check on his dog. He said it was a 3-hour drive from where he was at. He said what city he moved to recently, and I told him it was not a 3-hour drive. That it takes 1 hour to travel that distance. Google Maps says it is a 1-hour and 5-minute drive. I asked if he came from work. He said he was jobless at the moment. Either way, it should not have taken him 9 hours to get to his dog. I told them to get a rag and apply firm pressure to the puncture wound for 15-20 minutes. The bleeding mostly stopped after a while. I do not know why they were just letting their dog bleed until I intervened. They were obviously freaked out and didn't know what to do. I told them I was willing to cover half of the vet cost as soon as I could afford to pay them back. I estimated the price of the visit could be 800-1200 USD since it was after hours at the clinic. I gave them my number, and told them to email me photos of the vet bill afterwards. I was mostly frustrated because every vet clinic was closed by that point, so now they are going to an emergency vet clinic where the bill is twice as expensive. They had all day to get to a cheaper emergency vet clinic if they were not negligent. Either way I still offered. I walked back home and did some research on dog bites and legal action. Got very confused and scared that animal control might make me put my dog down or pay for the entire vet bill and pay fees (money I don't have). I grabbed my phone and walked over to their house to take photos of Sasha’s wounds in case we have to take legal action against each other. I asked to take photos, and the owner declined and said “not now” very aggressively. I talked to his mother about it, and she told him to let me take photos. I was unable to get photos of the side Sasha was laying on, but got the wound that refused to stop bleeding along with a few other injuries Bipsy caused. I spoke with him about how the vet may force them to contact animal control over this situation and that I would rather not get them involved. He did not seem very educated on the topic, and said the vets cannot force anything; they are only there to treat wounds. But if they do, my grandmother's home insurance may cover the costs of the vet bill. I recited the story to a few of the neighbors' friends, and they concluded that it was Sasha’s fault entirely, and that I was not obligated to pay. I already stated that I would though, even if I showed disdain towards the more expensive fees. They just left for the after-hour emergency clinic, and I am awaiting a visit and bad news. My dog has not been to the vet in over a year, and has not been updated on all her shots, so I am especially worried that this will cause a lot more issues if legal action is required.

Will the vets force animal control to contact me? What is the likelihood that legal action will be forced in between us? Am I at fault? Will either of our dogs have to be euthanized? (First offense for my dog, unsure about Sasha.) Will my grandmother's home insurance cover the vet bills if we have to pay? Can I counter sue for property damage and anything else if they decide to take legal actions? Will I be forced to cover the entire vet bill?