Continuity mistake: Doug, Mark and Carol are in the lounge having pizza and Doug has just told them he's the new Pedes ER Attending. Carol asks Mark, "Aren't you thrilled?" Mark is holding a paper cup. A split second later, his cup's gone and his hands are apart in front of him. Doug says, "He's got his doubts," and now there's a cup in Mark's left hand.
Continuity mistake: When Peter and Elizabeth are in the locker room having a serious talk, Peter's tying his tie - but when the shot is from behind his shoulder, his tie is completely undone. When the shot is on Elizabeth, it's partly tied. This continues for a few shots.