The actual guest was George Clooney. Tarantino just happened to be backstage when he was blindsided.
And Hellhound, don't go too hard on him. I thought he fired back well given that he was probably just standing around backstage having a beer when it happened. I thought it was funny at least.
And I don't have a way of getting this on the web, but if I ever find it, I'll definitely post a link.