When Sideshow Bob is shocked by Marge his hair goes up into a big round Afro like the one he had in his first appearance in "The Telltale Head"
When Homer and Sideshow Bob enter the Kwik-E Mart, Bob remembers that he robbed the mart while dressed like Krusty in "Krusty Gets Busted" only to be foiled by Bart. Apu even remembers Bob's robbery. Homer was also there when it happened but he doesn't mention it.
Sideshow Bob shot himself out of a cannon during the parade, which was also a reference to him being shot as Krusty's sidekick in "Krusty Gets Busted".
Frank Grimes Jr. is the son of Frank Grimes from "Homer's Enemy".
Grimes' death scene from the episode was shown again while his son was discussing his death.
Though Homer doesn’t remember Frank Grimes until Junior reminds Homer of him, Homer also remembers Frank Grimes wasn’t married.
The scene were Bart says he's going to throw a Baby Ruth into the pool is a reference to a scene from the 1980 film "Caddyshack".
Duffman's statement about Duff Stout being "The Beer that made Ireland famous" is a reference to the old slogan for Schlitz Beer (The Beer that made Milwaukee famous).
After the shot in Moe's Tavern, the door was rattling, opened and closed for several times. In the first couple of times, Frank Grimes Jr.'s tow truck can be seen from the door crack when door is opened, and then the door remained silent for a while, but then started rattling again - without the tow truck in sight anymore (possibly due to Frank Grimes Jr. just fled from the scene). This actually gives audiences a hint on the real murderer before the end of the episode, as the tow truck appeared before this scene, when Frank Grimes Jr. helped Homer towing his damaged vehicle.
From this episode on, Sideshow Bob is depicted with a lighter shade of yellow for his body and red for his hair.
Sideshow Bob references Frasier by saying Frasier's catchphrase, "Dear God!"
This is the last episode to air in 2002.
This is the only Sideshow Bob episode to be a sequel to a non-Sideshow Bob episode.
The drag queen that Homer dances with (a bald head and a large, greying moustache) is likely a reference to 1979 James Bond film Moonraker, where a character of similar appearance is seen dancing in the carnival parade when Bond tries to infiltrate Drax's Rio subsidiary.
Running Gag: Sideshow Bob keeps getting shocked by the shock button.
The episode was mentioned by Frank Grimes Jr. in Simpsons Comics 125. It was also mention by the comic’s editor.
Lisa claims in this episode not to like children's author Dr. Seuss, but, in "Lisa the Simpson", she mentioned that Yertle the Turtle was the greatest book ever on the subject of turtle-stacking. She probably likes that book, despite not liking the author. It is entirely possible to do that.
In the scene where Homer and Bob are chasing Frank Grimes Jr. in the FXX version, you can see his cape fall off. Then you see Homer and Bob again. But when you see FG Jr. again, he is still wearing his cape. Then, when he turns into the alley his cape is gone again.
When Bart closes his window, one of his eyes is briefly missing.
After Moe's pickle jar gets shot, there is a shot that goes to the wall and slowly looks at each picture. When we first see it, there are six pictures shown. Two larger ones on the right side, and four smaller pictures vertically down the left side. The picture in question is the large one in the bottom right corner. Originally, it is Moe in Egypt with the jar, and then when they do all the close up pictures, it suddenly changes to a picture of Moe and his jar laying on the beach.
After Bob stabs Bart's pajamas with the knife, his stomach is visible, but when you see Bart looking at his watch, it isn't visible, but when you see Bart again, you can see it again.
Exactly how old would Frank Grimes Sr. have been when his son was conceived? If we assume the present day of "Homer's Enemy" was the same as its airdate (1997), that would make a 1962-born Grimey around 35 when he died, and Grimes Jr. doesn't look much younger.
