AIUI if he his coughing fit had actually rendered him unconscious, he would not have paid any penalty even if he had killed the children. He would not have been responsible for his actions at that moment, being unconscious, so could not have been driving carelessly. We're told there are about 25 cases a year of "death by unconscious driving", I wonder how many cases there are which never come to light because no one, or only the driver, is injured?