After the worst in-season network debut rating ever last week, NBC’s Do No Harm (0.7/2) did itself more harm by falling 22% from that January 31 debut. To put it in further perspective, viewership of the certainly soon-to-be-cancelled new show fell from the 3.3 million who watched last week to 2.18 million. It wasn’t all bad news on NBC on Thursday, however. With the end of 30 Rock last Thursday, this week saw the long-delayed return of Community (1.8/6) for a fourth season at 8 PM. The comedy bested its previous season opener of September 22, 2011, when it wasn’t facing American Idol, by 6%, and beat its May 17, 2012 Season 3 finale by 38%.