Was Carl a liar?

There is something rather disturbing in season 6 which displays in my opinion Carl's tendency to lie - in the episode where the family (except for Harriet) expresses their disgust (in Carl's case) with Steve, Carl says something that wasn't Steve's fault (obviously the clips are Carl telling the story) - the opening to the "Buds n Buns" episode, where the griller explodes -- that one was Carl's fault not Steve's, Makes me think Carl is a liar, but then again he's always come off as a jerk.