My reasons for this are a) it is very difficult to find any pre-2005 citation for the joke, despite one supposed reference from 1975; b) the details of the story don't seem to me very plausible given what I know of comedians; and c) it's the kind of thing Penn Jillette would do.
So the story may have already played out in the modern era, if not in this case then perhaps in others: the 'Net is so full of nonsense and mis-information it would be very hard to tell. Social fragmentation of information sources likely makes it even easier today... you could argue that Birthers and the like are an example of this kind of hoax (or victims of it.)
It's a peek into the insider game of comedy. Every group has some gag, some saying that gets circulated that doesn't leave that group due to lack of context -- you had to be there type things -- or due to it being risque and taboo, like the Aristocrats. A similar thing for newspaper writers would be the Order of the Occult Hand [1], in which writers tried to slip that phrase into copy without the editors discovering it. These things are not cataloged because cataloging them would defeat the whole purpose. While the net has a lot of info, there's quite a bit of inside baseball that doesn't make it online.
Gilbert Gottfried used the joke in 2001 after a 9/11 joke backfired terribly, although the movie was apparently already in progress then, the author of the article says it was a well-known inside joke. http://observer.com/2001/10/observatory-6/
My reasons for this are a) it is very difficult to find any pre-2005 citation for the joke, despite one supposed reference from 1975; b) the details of the story don't seem to me very plausible given what I know of comedians; and c) it's the kind of thing Penn Jillette would do.
So the story may have already played out in the modern era, if not in this case then perhaps in others: the 'Net is so full of nonsense and mis-information it would be very hard to tell. Social fragmentation of information sources likely makes it even easier today... you could argue that Birthers and the like are an example of this kind of hoax (or victims of it.)