The author presents the results of the critical analysis of the materials of forensic medical expertise of a case of the serious harm to health that has led to involunry manslaughter. According to the expert opinion, the death resulted from the traumatic shock associated with the combined head and the chest injury. Such conclusion levels out the difference between the two accused persons and their "contribution" to the extent and severity of the inflicted damage to the victim's body; thereby, it equalizes the degree of their guilt and criminal responsibility. The present study showed that such interpretation of tanatogenesis associated with the combined injury is erroneous. The death of the injured person resulted from cerebral coma that developed following a severe craniocerebral injury as a constituent component of the combined trauma. It is emphasized that the thorough investigation of tanatogenesis based on the reliable elucidation of the immediate cause of death makes it possible to avoid poorly substantiated expert conclusions and their potential dire legal consequences.