Your Father lives because of the personal and private decision he made and now he has to deal with his daughter ratting him out to elders?!. So now, this becomes a congregation's body of elders decision whether he should have really lived or died and then impose that verdict on him...basically, "well, you may have preserved your life, but, we are going to give you hell about it."
I'm going to say something really profound! I let you know when I am going to say something really profound so that you will know and will say to yourselves, "this is profound". I would immediately contact a lawyer and the police for Elderly harassment, bullying, endangerment, and abuse, etc. He made a private decision and this should be covered by HIPPA Laws. This is what just chaps my buttox, is that the Congregations or their members (your Sister) even feel that have this kind of authority. Does your Sister have anything financially to gain in this? Just Asking.