Animal Welfare Professionals

Just found the owner of a cat that has been feeding at my house. Two days prior the cat had been in a fight as he had a swollen eye and a mark above the rye where an infection set in. I was able to open the scab and drain the pus as well as clean it with betadine. The owner took the cat to the vets and it tested positive for FIV. My question is could it have gotten FIV from that recent fight.

FIV is possible because it has fought with other cats that are unknown of their health. To avoid infection (the swollen eyes and FIV), you're better to separate it or send it to the vet for treatment. Then you could publish some posts in the group near you. But if it has no response, it might be a stray cat, you can consider to adopt it.