Well i think Zidane was right because no one can stand any person saying bull sh-ts about his family specially to his sister and mother.Zidane is known as 'Mr.cool'as he had never faught or argued on any sort of act but this time he head butted Matterazi,that means Matterazi really said something bad or abusive about his family and religion.The lip readers also prooved that Matterazi abused his(Zidane's)siter,which is not right.