What happens if a realtor makes a mistake?

My husband just recently purchase a HUD home and he had expressed to the relator way before went to closing that he wanted to add me to deed of the home. We both went to closing and sign all the paper work to add me. However, our realtor forgot to send an addendum with our HUD contract so I could be added to the deed of the home. When I called HUD they said that we would need to hire an attorney to a survivorship so I could be added. I feel the realtor should pay for this to be done. Does any one know what rights we have if the realtor makes a mistake?