Why Did Zidane Headbutt ??

In an otherwise scintillating final, the one act that left a sour taste in the mouth was the head butting by Zidane. This was something that was completely shocking. It was sad to see the whole French team on the podium but not him. I hope that history will be kind to him and not judge him by his last international act, but keep in mind the amazing game of this legendary midfielder.