The twelve million dollar check Mr. Burns hands to Lisa at the end of the episode reads "4/27/97", while the episode aired on April 20th, maybe implying that the events depicted lasted only a week.
The first definition in the Dictionary in Mr. Burns head is ragamuffin A ragged often disreputable person: A poorly clothed often dirty child and that is what he calls Lisa.
When Lisa tuns down the money it should sting but Homer owns the Denver Broncos(which made a profit of $82 Million In 2016) as seen in You Only Move Twice so it shouldn't be the end of the world.
The Books Homer recycles are Dickens and Leon Uris Author of Exodus(made into 1960 film), Battle Cry(Made into 1955 film) and Gun Fight at the O.K. Corral(which was made into the 1957 Film of the same Name Starring Kirk Douglas who played Chester Lampwick of Itchy on The Day the Violence Died).
Mr. Burns tells a hippie to "shine on you crazy diamond", referring to the song by Pink Floyd of the same name.
One of the books Homer tries to throw out is titled 'Dickens'.
The montage in the middle with Burns begging Lisa to help him is a reference to the opening sequence of the TV show, "That Girl".
The wrestler who buys Mr. Burns’ house is Bret "Hitman" Hart. The 8th of 12 kids(8 boys 4 girls) of Stu Hart all of which are/were Pro wrestlers or in the wrestling business in some capacity. The Hart Mansion in Calgary Alberta, Canada is a vary famous house The Dungeon (Training Gym) was in the basement where many wrestlers trained The house was designated a Historic Site in December 2012.
The song that plays while Mr. Burns is asked to join the other old men dancing but refused to do so is named Achy Breaky Heart.
In the faraway shot at Mr. Burns' office, Burns' suit is black instead of its usual blue.
The pro wrestler who considers buying Mr. Burns' mansion loses the muscle definition on his upper chest while he talks.
Lisa, Homer, and the rest of the family could clearly see Mr. Burns's check has “TWELVE MILLION” written on the bank order, as well as $12,000,000.00 written in the box. Homer obviously knew the check was worth twelve million dollars instead of twelve thousand.
In episodes taking place earlier than this episode, it is stated that Burns is a billionaire. However, he is worth approximately $100 million at the beginning of the episode. If he had lost at least nine hundred million by the time this episode takes place, he must have known he was losing money. Burns may have been senile, and thus ignorant of the amount of money he was losing. On the other hand when Burns sells the plant to the Germans it is sold for $100 million and he is ecstatic about that and thinks it is retirement worthy.
At the end of this episode when "Code Blue" is said in Spanish dub it is said as "clave roja" which means "red key" or rather "code red". The "Red Code" is said when the building is on fire but since Homer's heart had stopped they should've said "Código Azul".