Wait! What about her rights?
If she does not feel safe, she needs to tell them so. They would be negligent to send him home if the knew there was any danger to her safety. Physically or mentally. Can you get your objections on the record?

Bobcat's (husband) stepfather (who raised him) turned violent in his later years and attacked Bobcat with a knife. If Bobcat hadn't done wome quick thinking and wrapped his arm up in a sheet, he would have been severely injured. His stepfather felt awful when he came to his senses (after months in a psychiatric hospital) but Bobcat could have been killed.

Your father is unpredictable. You mother has rights too and her safety should come first. How can we get the hospital to acknowledge that.