Someone doesn't understand how death certificates work. The cause of death is the condition that starts the chain of events that leads to someone dying. In other words, if that condition was never present, the patient would have survived.
To use an analogy, if a person is shot to death, technically that person would have died of organ failure or blood loss. However, the shot was the thing that caused the chain of events that led to that person's death, meaning that that is the cause of death. It really isn't that difficult to understand.