Quran is the only Holy text which is completely intact, unlike Torah and Bible which have been distorted and changed into many different versions.
There is possibility at of misquoting the prophet Muhammad (SAWA) while writing the Quran as the Prophet and the writer (Imam Ali) both are Infallible supported by Allah (SWT) and His Angles. Allah (SWT) has promised to keep the Quran intact ( Verily, We Have sent the Thikr (Quran) and We will be guarding it (from corruption))(انا نحن نزلنا الذكر وانا له لحافظون )(Sura 15, verse 9)
The Prophet (SAWA) has recited the Quran and supervised writing it. No question at all of any error in writing the Quran as all the Infallible Imams read the Quran in the same way which confirms that there is no error whatsoever.
The fact of the purity of Quran is admitted even by the enemies who tried every thing to harm Quran but could not as Quran is protected by Allah (SW) and no one or power can make any change in Quran as it's enemies tried and failed.