Yes it is a huge insult to throw shoes. Isn't that why that English couple accused of having sex on a Dubai beach got in to even more trouble? It was reported that she threw her sandles at the police man who arrested them (she denies it).
If it were the other way 'round, their more fundamental factions would be marching on the streets, burning effigies and so on. But apparently, the guy who did this is being hailed as a hero.
George Bush just ducked and shrugged and then smiled like he can take the insult on the chin.. Good for him I say. And that's the first time I've said that.