I thought Zidane cracked because he already was in pain from taking one to the shoulder, rather than the fact that Materazzi was ragging on him. I don't recall Materazzi going out of his way to piss him off more than that one time (and boy, did he get what he had coming)... at least, not captured on camera. I guess we'll never know.
It was a tough game and while France had the upperhand, Italy stood their ground like nobody's business. If they hadn't scored in the first half, the game would've probably been France's, I recognize that much. France worked them to exhaustion in the second one.