this morning, the BBC elaborates on a possible motivation:
Zinedine Zidane's agent says the French captain headbutted Marco Materazzi in Sunday's World Cup final because the Italian made a "very serious" comment...
Sources in France say it is believed that Materazzi insulted Zidane's mother.
ok, first of all, "sources in france say it is believed"? could a more shaky attribution for an idea be concocted? and secondly, even if materazzi did insult zidane's mother, are we supposed to imagine that this was the first time zidane had bumped up against a "yo mama" joke on the pitch? please. i'm sure zidane has handled slander, libel, and heresy against his mother many times before, and still managed not to knock someone to the ground with the top of his head. you think he could have managed the same kind of restraint for 20 more minutes.
regardless, i'm still dying to know what materazzi said. who isn't?