Umar Bin Al Khattab: Different recitations

Narrated 'Umar bin Al-Khattab: I heard Hisham bin Hakim reciting Surat-al-Furqan during the lifetime of Allah's Apostle, I listened to his recitation and noticed that he was reciting in a way that Allah's Apostle had not taught me. I was about to jump over him while He was still in prayer, but I waited patiently and when he finished his prayer, I put my sheet round his neck (and pulled him) and said, "Who has taught you this Sura which I have heard you reciting?" Hisham said, "Allah's Apostle taught it to me." I said, "You are telling a lie, for he taught it to me in a way different from the way you have recited it!" ..