This is the only episode where a work location (but not an occupation) for Thelma Lou is mentioned. When Barney is trying to get her and Helen to reconcile, she says, "I have to get back to the office."
Barney tells Andy that he goes to church with Thelma Lou every Sunday. At no time in the series are he and Thelma Lou shown in or around the church together. Though he may mention her, Barney is always by himself there.
This is the second time in the series that Andy sings 'Red Rosy Bush' to his love interest (Helen). The first time was in season 2, episode 27 "Three's a Crowd" when Andy sung the song to Mary Simpson #2.
Andy, Barney, Thelma Lou, and Helen are the only characters appearing in this episode.
When Andy and Barney are arguing about Helen (in the courthouse), you can see a framed newspaper in the background, With the headline "Deputy Fife Hero In Cave Rescue." That is a reference to what happens in episode 13 of season 4 ("Barney and the Cave Rescue"), In which Barney apparently rescued Andy from a cave (although Andy actually orchestrated the entire event to save Barney from embarrassment).