Ferrell and McKay developed the show together and apparently this was a role Ferrell had wanted for years and it was developed with the intent of him playing the role. Then McKay gave the role to John C. Riley and the first Ferrell heard of it was when Riley called him up to say that he'd gotten the role. That's what led to their break up.
David Spade did that to his best friend and assistant. Promised the guy a part in some movie and told him he would be on camera talking. Guy was all excited and tells his family "I'm going to be in a movie", goes to the set and then gets told "No, Adam Sandler wants one of his friends in the part, so you're not in the movie anymore". Spade just told him "Whatever" and laughed and said "it happens".
So the guy waited for Spade to come home drunk one night and then 'broke' into Spade's house with his set of keys. Spade is about to pass out in his bed from being drunk when this huge 6'6" shadow is standing in his doorway and he sees it and moves to get up. Guy hits Spade with a stun gun and tries to grab him to strangle him but Spade flees the house out the window. This guy was also drunk and on coke and like 400lbs and falls over and sprains his ankle trying to chase Spade down and kill him. So Spade runs back inside and goes under his bed and grabs his shotgun and calls 911. Later Spade realizes that the guy had looked for the shotgun under the bed but couldn't find it because Spade had moved it a day before to being under another part of the bed.
Later David Spade tells everyone it was some big misunderstanding and that his guy was really a "good guy". Which means that this dude probably knows that Spade is a closet fag or rapist and knows where the bodies are buried.