The fundamental particles, kingon, queons and republicons, all travel at the speed of light, and are presumably massless. In the timeframe of the photons, and other politicons, they travel instantly from point A to B; so they communicate the King swap instantly.
The solution of the paradox is that each object has a unique inertial frame. Therefore, the King is not dead until the light cones of the dying King and his subject intersect. If the Queen of England dies in London, she's still alive to her subjects in Auckland for 4 hundredths of a second until the news reaches them through the center of the earth.
That's 40ms for light to travel through the Earth. Lag in New Zealand must suck.