My brother is the trustee for my Mom and Dads will. My Dad passed in April and my brother had my Mom move in with him. He had a notary come to his house and made himself with my Mom’s signature make him her POA. She has dementia and didn’t know what she was signing. I was fine with it because he was taking care of her. After four months he said he could no longer care for her so she moved in with me. I asked to be on the account her SS and my Dad’s pension go into but he said no. I would need to give him receipts and nothing can exceed $100. Without his approval. I would be given $350. A month to cover food, clothes, toiletries but he would reimburse for doctor and RX co pays, depends, grooming. I asked If something happened to him how would I have access to her accounts for her care? He said a trust attorney had instructions so it would be fine. When I pushed for trust attorney contact info. He now says we don’t need one and I could use my equity line of credit until things got figured out if something happened to him. Should I just not worry about this or have something in place if needed?
My feeling is that this is all vague, he is changing his story, and changing the care arrangements after setting it up for himself. He is giving you all the obligations, and he doesn’t account to you at all. It may all be on the level, but you have no way of finding out. The disappearing 'trust attorney' is the most worrying bit.
If you are paying for all the outgoings and he reimburses you after you provide all the receipts, it would be more sensible for you to be the financial organiser yourself. It doesn’t sound good, you don’t understand the legalities (it's possible that brother doesn't understand them either), you are not safe, and neither is M.
My suggestion would be that you say that you are unable to care for M unless you have a clear understanding of the finances and the decision making. I’d take M back to him to care for until you get details. I think you probably need a lawyer to check any story he gives you.