Indeed, I didn't claim otherwise. The point is that the US government wouldn't have prosecuted him for insulting a foreign leader.

Yes but pointing the finger at this is quite loaded in the current context. Much less would it be to denounce laws as desuete as this French law forbidding women to wear trousers: http://newsfeed.time.com/2013/02/04/it-is-now-legal-for-wome... Of course the law itself was so antiquated that noone in their right mind would follow it.