The vet was 10 miles away but, what about the lady that took her into the vets?
My neighbor had a cat disappear all winter and then showed back up come spring. They had a guy come buy hay that saw him and said, "Hey that's my wife's cat!" Come to find out the cat had wandered to their house and his wife had taken pity on him as it was cold outside. He spent the winter indoors and come spring insisted on going outside. That's when he disappeared from their place and went back to his first home. It seems to me he did this for a couple of years.
I had one that would come visit me every morning while I waited for the school bus. He would be there every afternoon when I got home. But, he wasn't there during the day. Come to find out he was traveling back and forth from his home to see me twice a day. His home was 1 1/2-2 miles, oneway, away!