I find his argument compelling and genuine. Comedians do "lie" on a regular basis to create comedy. You don't have to look very far to find other examples of this. This is why the line "--this is true!" is often heard during a late night monologue, because the comedians embellish and invent so often that when something sounds like an embellishment but isn't, it's even funnier for them to point out that their writers didn't make it up.