From wikipedia
http://en.wikipedia.org/wiki/Zinedine_Zidane Since both players refused to comment on the incident, there are various allegations about what led to Zidane's violent outburst. His agent, Alain Migliaccio has claimed that a "very serious" comment by Materazzi provoked the attack.[7] Reportedly, the deaf forensic lip-reader Jessica Rees was employed to analyze the video sequences with the help of an Italian translator. According to these reports, Materazzi spoke in Italian - a language understood by Zidane due to his time spent with Juventus F.C. - and first told him: "Hold on, wait, that one's not for a nigger like you." As the players walked forward, Materazzi allegedly said: "We all know you are the son of a terrorist whore." Then, just before the headbutt, he was seen saying: "So just f*** off." [8] [9] According to Brazilian TV Rede Globo, a lip-reader claimed that Materazzi twice called Zidane's sister a prostitute.[10] Earlier claims about Materazzi having called his opponent a "dirty terrorist" have been denied by Materazzi, who reportedly said: "It is absolutely not true, I did not call him a terrorist. I'm ignorant. I don't even know what the word means."
www.wallak.net/zidan/
Author