Yeah, it's even more obvious if you watch this:
http://www.youtube.com/watch?v=mNB_ntQCN98
They tried to parody that clip with the scene in Franco's bedroom but what Riff Raff says is 100 times funnier than what Franco says. This ain't no middle of the mall shit! Seasoning sauce been staying on deck! Stupid flatscreen, dumb shit, retarded short bus shit! Just finished filming my other shit that I was supposed to have been did...
Even more strange when they got the twins and this guy, both of which are real people who actually act like they do in the movie. Why not just do the same with Riff Raff? Don't give him lines, just tell him the gist of what he needs to say and he'll come up with some hilarious dumb shit on his own.
FLATSCREEN. DUMB SHIT