No, I didn't say that they "WANTED" a violent outburst, nor was I even assuming that. That's why I compared it to Clint Eastwood's "Go ahead make my day," a line used in a scene where Dirty Harry had his gun pointed at an armed robber who had his gun pointed at an innocent woman. Obviously, Dirty Harry didn't want the woman in the scene to get shot, but he was making it clear that he wasn't going to back down, give in, or surrender no matter what.
They were prepared for it. That much is obvious, since they knew enough to post armed security and have cops standing by.
I don't know what kind of "counter-argument" one can expect to a cartoon depicting Muhammad.
I agree completely with what you're saying here. We have rights in this country, and people have a right to draw cartoons, criticize/satirize religion, burn flags, and many other things guaranteed by our Constitution. Anyone who lives in this country has to get used to the idea, however offensive it might seem.
But even then, one has to make allowances for practical reality. As a counter example, if a person dressed in a KKK costume went to Baltimore and jumped into the middle of the riots shouting the "N word," what do you think would happen to that person? Technically, he may have the "right" to do that, but I would still make the observation that it's probably a dumb thing to do.