Think Sam Kinison ever told a version of it?
I wonder about things like that. The deeply wrong premise would likely have darkly amused him; on the other hand, it was a vaudeville routine that kept going through the comedy scene throughout the decades, and maybe it was too "old-school comedy" for him. I have trouble imagining Kinison getting into vaudeville.
Still: maybe once or twice or more times than that, Sam Kinison idly or seriously said "So, this guy walks into a talent agency..."
Or maybe they tell the joke in Comedian Heaven. Or Comedian Hell, depending on wherever you think Kinison wound up.
* I say "supposedly" because the fullness of time may possibly yield AN EVEN RUDER JOKE. As Sam Kinison himself once said, "People in the audience are going 'Jesus, God, that's the sickest, most disgusting joke I've ever heard on stage.' WRONG! I can top it."