My brother is signing our mother out of the nursing home. What can I do?

My brother, despite everyone else telling him he will be sending my mother to her death, is planning on signing my mother out of the nursing home and sending her home with 4 hours a day of a Medicaid home health aide. Everyone has tried reasoning with him, but he will not listen. The nursing home says their hands are tied as he is signing that he will be responsible for her care. However, he is a compulsive liar and will definitely not doing any of what he is saying. I have repeatedly told him and anyone else that if she goes home, I will not provide ANY assistance. I know that will be tough when she is crying on the phone to me. I am at a loss as to what to do and know it will be difficult to maintain the hands off approach until this horrible experiment inevitably fails.