Character mistake: At the party, Fred is supposed to make a bbq, feeding about 50 people. But once he's got the fire going, he puts two lonely pieces of hamburger meat on top, to cook - only two.
Character mistake: Fred is asked, over the phone, to a monthly cinema gathering and debate. Having heard the phone call on tape, Stan comes over and tells Fred he is crazy to even think of going. Fred says he'll get the film and watch it, then go to the debate. But they don't "get the film", they "go" to the cinema, to watch the film, along with about fifty people, then have the debate.