Report that it is nowhere written in the Koran that it is blasphemous or heretical or forbidden to draw or paint or represent an image of Mohammed. Also, it is impossible in Islam to misrepresent or distort a representation of God, because the Koran teaches that God is unseeable, unknowable, inconceivable in a human way.
More, Mohammed is human, a prophet, not divine or semi-divine in any fashion. To represent him is to represent a human being who was born of a woman, lived as a merchant and husband, died a mortal death in his day. This is not similar to provocative vulgarity about Jesus Christ, or about Yahweh or Jehovah or the Lord God Almighty. Mohammed was a man, two arms, two eyes, one brain. The only reluctance to be found in Islam about drawing Mohammed is the teaching of various characters that to picture Mohammed is to encourage idolatry. However, the rioting over Mohammed's image is a direct result of such dimwitted and proscribed idolatry.