Taking a life because of an expression you are not even being badgered to see or recognize is clearly an injustice at the highest level no question about it (some lives in what happened in France were taken even without choosing to make such expressions). However, if we want to talk about the issue of tolerance to freedom of expression you might be surprised by how much of the intolerance you see in Muslim countries to such expressions  is about the form not the content. On the other hand I would see much less problem with the intolerance in western countries to any questioning of the Holocaust if that intolerance was as much limited to the sarcastic or joking type about the issue. Actually, the last time I checked it seemed that the stand against the freedom of expression by some Western countries in that goes beyond that of a tolerance issue to a prosecution and some writers are wanted just for expressing views questioning the Holocaust.   

Any Muslim thinks that his prophet accepts from him to shed blood or even inflict any kind of harm on another person just because of a cartoon, is showing a deep ignorance of the Prophet that very probably could exceed by far any ignorance of the maker of these cartoons himself about the Muslims Prophet.