According to the internets, "when a person leaves home on a journey, throw an old shoe after him so that he will have good luck (Superstitions: 10,000 You Really Need)."
Remember that dude/journalist who threw a shoe at GWB when he was giving a speech in Iraq? Perhaps, he has been misunderstood. Maybe he was just wishing GWB safe travels on his way back to the US? No?
I'm calling FoxNews!