This story is just one of most likely thousands of similar stories that could be told about outdoor cats.
It doesn't matter what kind of "situation" your cat has at home. They need you to be a smart and caring pet owner and they need to stay inside. Always.
It's unfortunate for the cats that sometimes their owners think they have valid reasons to let the cat roam "free".
It's even more unfortunate when owners make no sense at all and their reasons are illusions they made for themselves.