Addressing rumors that the "Insheeption" episode of South Park ripped off College Humor's Inception parody "Inception Characters Don't Understand Inception," Matt Stone set the record straight in The New York Times on Friday:
Mr. Stone said he and Mr. Parker wanted their “South Park” episode to satirize the verbal complexity of “Inception.” “It was like, ‘Let’s parody the gobbledygook – because honestly, that movie – all those explanations, and explanations of explanations,” Mr. Stone said….
“We thought their joke was that a lot of those lines were actually in the movie,” Mr. Stone said, “and they were banging them against each other, and showing that the ‘Inception’ characters didn’t even know ‘Inception.’ That was a mistake, and it was an honest mistake.”
It sounds like a case of Parker and Stone not doing their homework. The two should have referenced their source material (which, admittedly, is pretty "goobbledygook"). Dan Gurewitch, the co-creator of the College Humor Inception parody, was forgiving in his blog as only a devout South Park fan can be, mentioning how he "admire[s] Trey Parker and Matt Stone more than almost anyone currently working in comedy" and generally feeling sorry for calling out South Park despite the fact that they'd clearly plagiarized him.
Both sides were nice about it and both sides apologized. (Though, Gurewitch didn't have to be as gracious, and Stone could have been less full of excuses.)