This episode deals with Season 8 episode 15 "Legacy" , in which Frank wrongly terminates an officer, who was within her right to do what she did, the actress returns to play the same character in this episode. He confronts her numerous times to make amends and admit his mistake.
When Jamie and Eddie kiss at the wedding venue they just agreed on, there is a door behind them with a sign above it in old German letters saying "Der Notausgang", translating to "Emergency Exit".