No legal liability will fall upon the doctor for giving an opinion on phone for cases not seen by him as there is no contract between him and the patient. For negligence to be proved there has to be a duty, breach of that duty and resultant damage. In this case there will no breach of duty. But, if the specialist has charged a fee for his opinion from the patient (patient can sue) or from the physician (patient and doctor both can sue), then he/she is liable. If the fee has been paid by the referring physician, it will be deemed to be paid by the patient.