This must be very upsetting. Is he actually on the title of the property or just on the mortgage. Trouble is, fighting him might be expensive. I think although the house would be considered as a joint marital asset, she may well be able to argue that a lot of this was accrued before the marriage. Unfortunately I suspect he will certainly be awarded something and she will either have to buy him out which is probably what he is aiming for. She is going to have to get legal advice as he is clearly not going to go away and the longer it goes on the worse it will get. She needs to get a divorce asap, I suppose the only consolation is that he has gone now and that she did not have children with him and get into all sorts of further entanglement with him. Hope she meets someone nice in the future.