Short answers, pulled from the story.
The United States Department of Defense defines killed in action as the precise instant a service member ceases to exist under hostile fire regardless of whether they ever drew a weapon. This classification applies to deaths resulting directly from a hostile attack even if the soldier did not fire a shot.
The United States Department of Defense distinguishes these categories based on the speed of medical intervention and the location of the casualty. Personnel who reach a medical treatment facility before succumbing to their injuries fall into the died of wounds category while those who die before reaching help are classified as killed in action.
Missing in action often evolves into presumed killed in action when bodies are never found in hostile environments like naval battles. The ocean frequently swallows the evidence of death making recovery impossible and leaving families in a state of suspended animation.
The Commonwealth War Graves Commission emerged to manage the vast number of unidentified soldiers from World War I whose bodies were never recovered. John Kipling was one such soldier whose missing status prompted the formation of this commission to honor those who could not be found.
The United States Department of Defense includes deaths from friendly fire within the killed in action category during the heat of combat. This classification acknowledges the tragic reality that comrades can be the cause of death while strictly excluding deaths from vehicle crashes or murder unless they occur within the immediate context of an engagement.