I suspect that due to variations in the earth's surface, and fluctuations in pressure due to things like air currents (and to a lesser extent perhaps even natur

I suspect that due to variations in the earth's surface, and fluctuations in pressure due to things like air currents (and to a lesser extent perhaps even natural and man-made formations) the shock wave didn't travel uniformly in all directions, and wouldn't have been audible from the antipode.