No one enjoys being accused of something he has not said or done. Angry denial is a common way for humans to react to unjust criticism.
مَا مِنْ أَحَدٍ يُحِبُّ أَنْ تُوَجَّهَ إِلَيْهِ ٱتِّهَامَاتٌ بَاطِلَةٌ أَوِ ٱنْتِقَادَاتٌ مُجْحِفَةٌ .‏