Ken Jenkins previously appeared in the episode "The Virus" during season 1 as Stanley McGee.
Logic flaw: Keith says he hasn't spoken to his aunt since he was 12. But she recognizes him in the elevator, knows his wife's and son's names, and knew he was a doctor. She admitted to him that she was purposely staying away from his family. And he knew that she was still working and still at Johns Hopkins. His mother is deceased, and they are both estranged from Keith's father. So how would they each know those things?
Keith's mother died when he was 12 years old from complications of diabetes. He hadn't seen his aunt since his mother's funeral.
Fran Bennett previously appeared on Chicago Hope in the season 3 episode "Second Chances", playing Dr. Andrea Porter.
Mark Harmon (Dr. Jack McNeil) does not appear in this episode.