Unfortunately, transfusion errors continue to pose a major clinical problem. In practice there is a remarkable lack of understanding of the reasons behind transfusion medicine, a worrying disregard for protocol and an offhand attitude to bedside checking. Clearly transfusion medicine education, as often said, must be more extensively incorporated into the core curriculum of medical, nursing and laboratory staff. In this immunological case report, following accurate pre-transfusion procedures and routine laboratory testing, we highlight, once more, that it would be better for the patient to rely on proper bedside checking rather than on their own immune system in order to avoid serious side effects related to transfusions. Albeight this case we had "a happy ending", we must always bear in mind that one cannot compromise on safety and the quality care of patients.