The ending with Homer sitting on the couch eating pork rinds after saying he'd live life to the fullest is not the original ending. The original ending has Homer over at the Flanders' house barbecuing steaks as he promised he'd come only because he thought he'd be dead by then. Homer's father is also there still constantly telling Homer that he loves him and of course it's getting on Homer's nerves. Homer receives a phone call from the nuclear plant that he is to report to Mr. Burns' office at 9 am sharp tomorrow morning because he's in big trouble (for telling Burns to eat his shorts). Homer is now miserable. Marge walks up to Homer and says, "Homer, you are happy to be alive, aren't you? Aren't you?" Homer doesn't answer. This ending was said to be very good and fitting. However, it was deleted because it made the episode run too long.
Homer's list of things he wants to do on his last day on Earth are as follows: Make list (crossed out), eat a hearty breakfast, make videotape for Maggie, have Man-To-Man with Bart, listen to Lisa play her sax, make funeral arrangements, make peace with Dad, beer with the boys at the bar, tell off boss, [go] hang gliding, plant a tree, a final dinner with my beloved family and be 'intimate' with Marge.
Homer telling Bart that "cover for me" is a phrase he will find useful in his adult years is in fact a phrase that landed Homer in his current situation when the head sushi chef told the sous chef to "cover for me" so he could go make out with Edna Krabappel, and ignoring the sous chef's pleas that he was too inexperienced to prepare an order of fugu.
Fugu is in fact a poisonous fish if cut improperly. Sushi chefs must work for several years before being allowed to take tough tests in order to become certified to prepare it. The Emperor of Japan is also prohibited by law from eating fugu. Also, fugu is prohibited in the European Union, due to its toxicity.
On FXX, when this episode aired on August 21, 2014, also the first day of the "Every. Simpsons. Ever.", at the beginning of the episode, the TV-PG rating appears for about 2 and a half seconds before it disappears. But, after Homer says his catchphrase, 'D'oh!' the Rated TV-PG reappeared on the top left corner of the screen for about 15 seconds in this episode, making it for about 17 and a half seconds of appearance. However, in the repeat airing on FXX, this error was fixed.
According to Al Jean, it took them two days to convince the Fox censors to allow the scene of Bart and Lisa singing the Shaft (1971) theme song be aired because they thought the lyrics were too obscene to appear on television. In order to prove the censors wrong and show that it could appear on television, the staff dug up footage from an old Academy Awards ceremony at which the song was performed by Isaac Hayes.
When the chef of the sushi bar finds out that Homer has been poisoned, he yells at his apprentices in Japanese. The staff wanted the language they spoke to be actual Japanese, so they hired a Japanese actor who translated the lines for them.
The five stages of grief were first laid out in Elizabeth Kubler-Ross's book, "On Death and Dying." Though the original 5 stages went in the order of Denial, Anger, Bargain, Depression then Acceptance, Homer also goes through fear and does not go through depression.