Living will

I had my dad transfer from the hospital to a nursing home, just for rehab 21 days. When he got there since I was his health care representative, P.O.A, and care giver I signed all paperwork. I question was his code status, which he was full code. About a week later the D.O.N asked me about his code to. After talking to her for a few she asked if I would ask him again if that is what he wanted. So I did he said he would to stay a full code, I was fine with that and was going to follow that. We was getting things ready cause he was coming home on a Monday. That Saturday I got the call that I will never forget. You need to come, your dad has passed. I get there. The nurse said the ambulance just left and pronounce him. I only live 7 minutes away. The nurse said she came in and he was unresponsive. They didn't try anything. No C.P.R. nothing. Now the family wants me to take the nursing home to court. If anyone can give me some insight on this, I would appreciate it. My dad did tell me about 6 months before this that he wants to be around for at least 3 more years.