On a related note, this also is a reference to the Kennedys, as Maria Shriver, Schwarzenegger's former wife, is related to the Kennedys, and Maria, Rainier's wife, is implied to be related to the Quimbys.
Both drive a Humvee.
Bart also tells Wolfcastle his last movie "sucked," while Chief Wiggum says, "Magic ticket, my ass, McBain!" These are references to the critically panned Schwarzenegger film Last Action Hero .
The scene featuring Principal Skinner chasing Bart (both the music and animation) is based on the Gunslinger's chase of Peter Martin from the film Westworld.
The plot of the episode is based on the movie 12 Angry Men.
The chalkboard gag is a reference to a song from 1976 film Bugsy Malone.
Skinner picking up the cigar butt in the hotel room with an umbrella references the opening credits of The Odd Couple.
In the court, Homer sings the jingle for Meow Mix cat food in his head.
Homer watches the "director's cut" of Free Willy, which features Willy the whale crushing Jesse to death.
Freddy Quimby's lawyer uses the Blue-Haired Lawyer's voice, but has a completely different character design. In the DVD commentary, the participants call him "Burns's Lawyer" without adressing the design change at all.
The character McGarnagle appears to be a spoof of the Clint Eastwood character 'Harry Callahan' from the 'Dirty Harry' film franchise.
The police chief in McGarnagle speaks like and resembles Dennis Franz's character Andy Sipowicz from NYPD Blue. Franz would later play himself (portraying Homer in a movie) in the episode Homer Badman.
There are pencils and Bart's nameplate on his desk, but when he stands up, they aren't there.
Bart's lip sync is off when he says, "The system works. Just ask Klaus von Bulow."