Norm Macdonald explains why Eddie Murphy wouldn't play Bill Cosby in 'SNL 40' sketch

This past weekend, Saturday Night Live managed to slip a Bill Cosby jab into the "Celebrity Jeopardy!" portion of its SNL 40 special — one that, according to alum Norm Macdonald, was supposed to be much, much bigger.

In a 110-tweet, 1900-word tale told across more than two hours on Twitter Wednesday night, Macdonald, a cast member from 1993 to 1998, relayed the story of how Eddie Murphy came to decline playing Cosby in the sketch. Ultimately, Macdonald says, Murphy decided that "the laughs are not worth it" and refuses to "kick a man when he is down." Instead, the part went to resident Cosby impersonator Kenan Thompson.

Given Murphy's brief, mostly straight appearance Sunday night, in which he thanked the audience after a long intro from Chris Rock, that's a bit of a shame. The joke, of course, goes all the way back to Murphy's 1987 special, Raw, in which he tells a story about a feud the comedian had with Cosby over Murphy's use of foul language. In that sense, it very well could have been a show-ender.

Or, at least that's how MacDonald tells it:

From the intial pitch, Murphy was tough to nail down, leading to substantial stress on Macdonald's part when Saturday arrived. However, he seemed to take solace in support for the idea of Murphy as Cosby from Lorne Michaels:

Murphy eventually arrived at studio 8H, with Macdonald ready to talk. And the two did for about an hour, leaving Macdonald with the impression that Murphy was in:

With everything coming down to the wire like that, it doesn't appear to have been an easy decision — an element that seems to make Macdonald respect that decision to an even greater degree:

Aside from that, Macdonald also discusses the origins of "Celebrity Jeopardy!," meeting Sarah Palin, and trashes the Rolling Stone ranking of all 141 cast members that put him at number 135. If you've got a minute, the whole thing is really worth a read.

Below, Macdonald's entire story, edited only for formatting: