Continuity mistake: This is when Homer is about to conquer the 'Ball of Death', on his third attempt. As he is going up, just after Lisa shouts, "Don't slow down, speed up," when Homer has his fingers on the brakes, the Ball of Death suddenly gets a lot bigger.
Continuity mistake: The thickness of the dome changes from when it's dropped on Springfield to when they are escaping.
Continuity mistake: The size of the round window in the church changes size throughout the film.
Continuity mistake: Marge and Bart discover the wanted poster of them at the gas station. When the clerk enters the scene, his shadow is cast on the wall, cork board and the wanted poster behind him. The clerk never moves, nor does the lighting ever change, but as he says "OK" after Marge asks for diapers, his shadow has vanished.
Continuity mistake: After Marge shouts into the megaphone for the bomb to be thrown, it cuts to Homer and Bart while they're riding sideways on the motorcycle, and the bomb's under Bart's left arm while he's holding onto Homer with his right hand, but in the following shots the bomb's under Bart's right arm while he's holding Homer with his left hand.
Continuity mistake: In the exterior shot of the Simpson house, before showing Homer and Marge watching the news about the silo being found in the lake, we see the side window (facing the Flanders' house, from which they escape later) is a horizontal sliding window. However, from inside the bedroom and also when they are escaping, that same window has changed to a vertical sliding window. The same thing happens with the other window on the opposite side of their chimney.
Continuity mistake: When Homer tries to convince Bart to come with him on the motorbike, he first holds the bomb in his right hand, but then it's in his left one in a different angle.
Continuity mistake: When Mayor Quimby asks Cletus to demonstrate the anti-pollution barriers around the lake are idiot-proof, his entourage is spread apart, but the next shot of Quimby shows his entourage bunched closer together behind him.
Continuity mistake: When Homer and Bart are trying to outrun the crack in the dome, they are falling towards the damaged "P" in the Springfield sign. From their view, the top of the "P" is level with the letters "S" and "R" but when they use the bent leg of the "P" as a ramp to relaunch themselves at the dome, the top of the "P" is scrunched down almost halfway down from the other letters.
Continuity mistake: While Marge and Homer are watching the news on TV note their bed's footboard, then when Lisa angrily rushes into her parents' bedroom to confront Homer, the footboard's style is entirely different, but when Marge pulls Lisa away from Homer the footboard changes back to the original style.
Continuity mistake: When naked Bart skateboards past Wiggum's squad car, the vehicle does not have a partition screen between the front and back seats, a rear-view mirror, or a side mount searchlight, but in the following shots all have suddenly appeared, with other changes.
Continuity mistake: During the church scene, Martha Quimby is wearing an outfit with sleeves, but soon she's sleeveless, then back to sleeves, and finally sleeveless again. Behind Martha sits Bernice Hibbert, whose pearls also disappear and reappear.
Continuity mistake: Throughout the movie, the exterior side wall of the Simpsons garage changes length significantly, even between shots.
Continuity mistake: In the wide overhead shots as the crowd starts gathering at the dome edge and when Russ Cargill's image appears, note the homes on the third block at the far left side of the screen, which change when Cargill says, "Believe me it's the last thing we wanted to do."
Continuity mistake: When the Simpsons enter church they walk past Dr. Hibbert and he's wearing a solid black tie, but when Grampa has the outburst Dr. Hibbert is wearing a striped red tie. (Also, the stripes at the tie's knot are the same direction as the tie blade, though when tying the knot the stripes would be going the opposite direction).
Continuity mistake: In the first interior shot of the church, there are nine rows of pews on each side of the aisle, with Mr. Burns in the last pew on one side and Mrs. Glick in the last pew on the other side, but when Grampa starts rolling around on the floor there are eleven rows of pews, with two extra pews on both sides behind Burns and Glick. Additionally, the Reverend's wife is seated in the first pew, but just as Grampa shouts, "Trapped forever," we can see the back of an extra pew in front of Helen. (The front of the raised pulpit has vertical wood panels, and the pew is solid).
Continuity mistake: At church, seated in the pew behind the Simpsons are Moe and Kirk, and in the pew behind Moe and Kirk are Disco Stu, Professor Frink, and six other people, but just as Grampa shouts, "Trapped forever," in this one shot that entire pew with Disco Stu, the Professor, and all the other people has vanished, but then the pew reappears.
Continuity mistake: While Bart watches from the tree, Homer brushes the pig's hair and carries the animal out of the room, then Bart turns to see Ned tucking his kids in bed, and when Bart turns toward Homer again the lower window has a center muntin bar, but when Bart aims his slingshot at Homer that muntin bar has vanished.
Continuity mistake: At the cabin, after watching the TV report about the "new Grand Canyon," when Marge puts on her robe there aren't any pockets, but in following shots two pockets have appeared.
Continuity mistake: While Marge and Bart are in the service station market, when Marge points to the beef jerky jars the end of the service counter is right beside the jars, but when the clerk fills the bag the counter is now much longer, past the cigar display.
Answer: Homer has been known not to make the smartest decisions, and the decisions he does make, he makes without fully thinking them through. Clearly he wanted to get some donuts as quickly as possible without thinking of any other ways, so he decided to ditch the silo in the lake as it would be the fastest way of getting it off his back, even if it's not the smartest. Also, putting that aside, he likely wanted his own pick of the donuts rather than have Lenny guess what he wanted.
Casual Person