Joint Tenancy Warranty Deed

I bought a house and the mortgage is in my name and I pay the mortgage but my son lives there now and reimburses me every month in the amount of the mortgage payment. At the closing I wanted the deed to be recorded into my Revocable Living Trust so if I died he would get the house. He is sole beneficiary of my trust. The closing agent said the Warranty Deed should be filed on a Joint Tenancy Warranty Deed with "my name and his name, as joint tenants and not as tenants in common, with right of survivorship, the whole estate to vest in the survivor, parties of the second part, the following described real propery,etc." . Now he has gotten in a mess with a credit card company and they said they are going to get a judgement against him for the amount due. He tried to work out payments with them without success. He told them he didn't have anything of value for them to take and they said, "Well, you have a house with your name on it" He told them it did not belong to him and that it belonged to his mother. My question is can the Attorney for the Credit Card Company file a lien on the house or get some kind of a judgement filed against the house? If yes, can I file a new Deed putting it into my Revocable Living Trust to keep that from happening? If yes, what kind of deed should I file?