What spousal rights does my Mom's husband have over her care?

My Mom is 90 and remarried 9 years ago. He is 89. My mother is in stage 3 dementia. Her short term memory is completely gone and even parts of her long term memory are no longer there. She is still gentle. She is 90 years old and remarried 9 years ago, Her husband is 89, Her house is no longer safe for her and her husband insists he is taking good care of her. However she has fallen once in the last two months. I prepare all her meds for her a week in advance but even doing that she sometimes forgets to take them. I've spoken with her husband. Last year an OT said that Mom should not be left unsupervised in her home. Her husband still leaves her alone when he needs to do things and says "Oh she'll be ok for a few hours." When I suggest memory care he says he takes good care of her and he wants her there with him. Mom however is unhappy because aside from going out to lunch she spends most of her time sitting on the couch picking at her lip or hands. I did get her to agree to go to a memory care facility in a week but am wondering what rights (outside of a guardianship) does her husband have given my siblings and I have both POA and HCPOA? Just a tad more background. They live in her house and she (I as POA) pay for meals on wheels 3 days a week and his monthly expenses are just half the utilities. So he gets by very easily on his monthly expenditures. I do believe this is part of the reason he wants Mom to stay there. I do appreciate all he's done the past several years but his unwillingness to do what's best for Mom at this point is making her a prisoner in her own home. I'd appreciate any thoughts on this. I did see a lawyer and he said her husband could go after a guardianship but I don't think he would go that route because of cost etc. So what other spousal rights does he have to prevent Mom from going to memory care?