With the absence of Jim and Pam, and Ryan having turned into a massive jerk, Oscar becomes the sane one at the Scranton branch. Oscar is well aware of this, and he is reluctant to get involved in any of the office drama. This leaves Michael at the mercy of the horrible advice of both Dwight and Andy.
Once again, Michael proves that he has no backbone, ability to make decisions for himself, or any real knowledge of the world. Instead, his knowledge base is limited to stereotypes that he has learned from the media, the input of his two most obnoxious employees, and without any of the usual balance from Jim. As with all stupid antics, they usually end in disaster. Unfortunately for Andy, he is unaware of the dreaded costume curse running joke, resulting in him damaging a woman's car.
As the problems continue in Scranton, they inevitably affect the honeymooning Jim and Pam. Kevin, in his low level ambitions, managed to occupy Jim's new office without any resistance at all from the rest of the employees. Without Jim to kick him out of his office, Kevin unintentionally unleashes one of the worst things that can happen to somebody that is on a vacation. It is predictable, that in the absence of Jim, things fall apart. Yet, it's also ironic that when Jim is in charge, his decision making abilities are no better than Michael's.