The first time the internet got upset about this was when the Glee version of the song got posted to various sites (including iTunes) in advance of the show being broadcast. That FIRST version of the song included the duck sound and the line "Johnny C's in trouble". Lots of people noticed it and blogged about it and as a result, the network appears to have done a quick editing job to delete those exact elements from the version that broadcast - they left off one whole verse to do it.