The only way either Materazzi or Zidane could truly put the incident behind them would be for the following to happen. Materazzi must say, "I provoked Zidane verbally. It was wrong for me to do that, and I'm sorry." Zidane must say, "I attacked another player on the pitch in the middle of a match. It was wrong for me to do that, and I'm sorry." Both apologies must be unconditional and independent.
Perhaps if they did that, we could focus on the fact that world seems to be exploding around us. (See: Israel attacking Lebanon, synchronized train bombings in Mumbai, North Korean missile tests, escalated fighting in Afghanistan.) But I sincerely doubt that they'd be willing to lay aside their egos and their pride. If they can't, then neither of them deserve to be called true sportsmen.