The incident in the second period of extra time brought a premature end to the great midfielder's career and he can have no complaints about the justice of it.
He might, however, have cause to question its legality as it is against FIFA rules for TV pictures to be used as a basis for a refereeing decision.
Zidane had been an ever-increasing influence in the match, in which he opened the scoring with a penalty in the seventh minute and almost won with a wonderful header in the 104th only to be denied by Gianluigi Buffon.
Then, after a French attack broke down early in the second period Zidane trotted back from the Italian area exchanging comments with Materazzi.
Something the Italian said obviously hit a raw nerve as Zidane stopped, walked back towards him and landed a fierce butt on his chest.
VOCIFEROUS BUFFON
Materazzi collapsed, Zidane continued on his way and the game continued. It had not gone completely unseen, however as several Italian players, with Buffon the most vociferous, approached the nearest linesman demanding action.
Replays were shown on the hundreds of televisions in the media seats, raising an audible gasp.
As the mayhem continued on the pitch Argentine referee Horacio Elizondo consulted his linesmen and, so it was later discovered, the fourth and fifth officials, who have access to TV but may have seen the incident live.
The result was the red card and Zidane, who was also sent off for stamping during the 1998 World Cup, walked away from football for ever.
Both coaches confirmed that the decision had been taken by the off-pitch officials, both Spaniards, but each coach took a different view on what that meant.
"It was not Materazzi who got the attention of the referee, it was the fourth and fifth officials who pointed out what happened," said Italy's Marcello Lippi.
"The French spectators didn't know what happened, they'll know when they read the newspapers tomorrow."
France's Raymond Domenech said: "The referee saw nothing, the assistant referee saw nothing and then we have the fourth official saying to the referee what happened.
"We have video in football and then the fourth official tips off the referee."
France striker Thierry Henry said: "If they want to use video evidence it's not for one incident, they should use it for everybody and they should look at Materazzi too."
Nobody in the French camp was saying what passed between the two players but David Trezeguet said: "Zidane can leave here with his head held high. There is more than football in life."
Materazzi refused to talk about the incident.
