The NY Times looks further:
Zidane was tired and frustrated, and Materazzi’Â’s words -— no one is saying precisely what they were, though Zidane said his mother and sister were mentioned -— proved too much.
“You’re talking about a situation of absolute intense pressure,”” Mr. Sagal said. “And you are talking about a player in particular who is unparalleled in his ability to stay narrowly focused. What you saw was him losing his focus. His strength became his weakness.”