JOEL MCHALE calls JUSTIN BEIBERS mom a BITCH???

In a recent SOUP episode hosted by JOEL MCHALE on the E CHANNEL. He was covering a incident where JUSTIN BEIBERS MOTHER was trampled by some of his fans. JOEL MCHALES attempt to make a joke lead to this, " Tell that BITCH to move out the way, there is no cure for BIEBER-FEVER." Now I wonder if that was something that JOEL came up with himself, or did the writers really discuss the reasoning of calling the kids mother a BITCH.