“The Ethicist’s” advice is for the woman to take herself out of harm’s way, and if another renter is raped, attacked, killed or injured by the mysterious squatter who probably has substance abuse issues or is mentally and emotionally damaged, well, c’est la vie! Her conscience is clear because she did the kind and understanding thing. Of course, the owner of the units will be sued into homelessness himself, but the inquirer rationalizes that problem by assuming he knows about the homeless guy.
Ethics Bulletin: The woman has an ethical obligation to make certain that the owner knows. Presumably Kwame would similarly advise the woman to keep quiet if she discovered someone was secretly living in her mother’s attic. The humane course, after all, is to just stay away from Mom’s home in case the secret resident is a serial killer or has rabies.
This isn’t a tough call! Living in a storage unit is illegal, violates health and insurance laws, and creates danger for the public. A citizen discovering such conduct has a civic, legal and ethical obligation to report it to 1) the storage facility and 2) law enforcement.
But The Ethicist and his woke inquirer are part of the dangerous—and growing–segment of the population who believe illegal immigrants should be welcomed and other law-breakers shouldn’t face punishment because its our fault that they have been forced by a heartless society to live the way they do.
Ethics Alarms 
You mean “out of sight, out of mind” isn’t the ethical choice? /s
I disagree about the cat. It’s not humane to keep a cat leashed to a milk crate outside in frigid weather. A pet’s ability to provide love and comfort is a thing of value, but it should not be at the expense of the pet’s health.
The cat situation is more complicated, but my analysis is 1)giving money to homeless people usually doesn’t help them, and sometimes kills them. 2) the cat was probably a stray. Is the cat better off with a flawed caretaker than with nobody, living on the street? Probably. 3) you’re going to, essentially, take something away from a vulnerable human being by exploiting his or her neediness so you feel better and 4) exploit your superior resources as power over a weaker human to remove one of the few pleasures or comforts that person has to bring no ultimate benefit of the human being, who will lose or waste the money, and then not have a cat/companion/source of comfort.
I think I would feel different if the cat were in his lap or had more protection from the cold sidewalk than a thin blanket. A stray would be able to get off the pavement and under a bush or behind a dumpster. So, no, I don’t think it’s necessarily better off with a flawed caretaker because he has her tied to a milk crate.
I would also consider buying a cat bed, food, and a water bowl for her, but the letter writer said they could tell “that he was mentally ill and unable to provide proper care for the animal” so I’m not sure how long those things would remain with the cat. If the man seemed able to care for the cat, along with providing necessities, I think that offering to have her spayed, vaccinated, and then returned to him would be reasonable.
I’m sure I’m a bad person for feeling more sorry for the cat than the man. The man has more agency than the cat and more options. It feels as though the cat is being treated as a thing rather than an animal. (It’s possible my judgement is affected by the illustration. That is one sad looking cat.) I don’t think it’s a fair trade off for the cat to be in an abusive situation just so the man has a companion. I would worry about her little toe beans getting frostbitten.
My late wife would look at the problem exactly the same way.
May I suggest a 9v battery heating vestment for the kitty? It warms up to a very comfortable 65 degrees and the battery lasts a week. I think this might by the must humane choice for all concerned. For the homeless man, for the kitty, and for the feelings of anyone observing.
This makes me think of a conversation between two characters in Pluribus.
Carol: “They’re not evil. They wouldn’t even kill an ant.”
Manousos: “And isn’t it evil to value a man the same as an ant?”
By worrying about the cat, I’m afraid I’ve slipped into caring more for an animal than a human, but it’s because I think the cat is likely to die if it remains as is while the man is not likely to die from the removal of the cat.
The show is on Apple. If you haven’t watched it, watch. We’ll have so much to talk about.