Jay,

I did mention above that there are limitations to the Freedom of Speech doctrine. However, they need to be properly invoked. If the words spoken constituted a threat, fighting words or incitement to riot, the proper complaint should have been lodged with the authorities for breach of the peace, rather than addressing the issue through violence . 

Even if the spoken words do fall within the exceptions, the one to whom the words are spoken does not have recourse to violence if there was nothing more than the spoken words. If the individual is threatened by violence he has the right to use reasonable force sufficient to repel the attack. In the absence of that threat, violence is not an appropriate remedy.
Unless I am missing something here, the gentleman at the next table did not threaten violence...he only made offensive statements with respect to those serving in the military.

Whether the words spoken would fall within this exception would be more appropriately determined by the trier of fact (judge/jury) rather than by the person who was incited to violence. The defendant would be in the position of having to raise the issue as a defense in an action for violation of constitutional rights. Do you think you would want to have to rely on this defense if you were in that position?

There would also be the matter of civil and/or criminal actions for assault and or battery.