Continuity: In an episode fairly late in the life of the show, Lou Grant says that when Mary came to interview for a job at the station, she bumped into the desk in his office and said, "Excuse me" to the inanimate object. However, we saw that interview in the very first episode, and no such thing happened.

Factual error: Bill Daily plays a bumbling politician in this episode, where he comes over to Mary's apartment on a Sunday evening. It has been definitely established that this is Sunday. When he shows up, he is wearing a kippah (yarmulke), and Rhoda (who is Jewish) comments, "I knew there was something I liked about you," meaning she is assuming he is Jewish. Then he takes the kippah off, and calls it a "beanie." He isn't Jewish. He says he has just been to a Bar Mitzvah. The problem is that Bar Mitzvah services don't take place on Sundays; Bar Mitzvah services are nearly always on Saturday. To be on a Sunday, the Sunday would have to be a High Holy Day (three days out of the year). Even then it's not usually done, and would be in the morning anyway. This episode aired at the end of the season, not the beginning, when the High Holy Days take place. To a gentile, this probably seems pretty obscure, but it bugs me every time I see this episode.