After the end of this season, the series was renewed for three more seasons. It marked the first time a TV series was renewed for more than one season at a time.
When Sheldon mentions "an eye for an eye" from the Hammurabi Code, he is not quoting the Bible (although the phrase does appear in St. Matthew's Gospel) but the legal code of King Hammurabi, ruler of Babylon in the first half of the eighteenth century B.C.
Sheldon mentions to Howard that he could take Bernadotte's last name. In fact, Melissa Rauch's husband took her last name.