Continuity mistake: When the wall is put up around the lake it is built right next to it, but when Homer dumps the silo the wall's much further away from the water. (00:21:15 - 00:24:05)
Continuity mistake: Barney runs head first into the dome and slides down horizontally. Next shot he is stood up and is shoulder barging the dome. (00:48:10)
Continuity mistake: When Homer is on the wrecking ball, he hits a fork on one side but in the next shot it vanishes. (01:01:00)
Continuity mistake: When Homer tells Lisa to clap in Alaska, there is some snow on his left ear that moves to the top of his head. (00:46:05)
Continuity mistake: When the dome is placed over Springfield, you can see Lenny and Carl in the middle of Springfield. When the dome goes over Moe's and the Church, Lenny and Carl are also at Moe's. (00:25:55)
Continuity mistake: When Russ Cargill spreads the five unthinkable options on the President's desk, the book's spines are all facing to the left, but after the President chooses option three, in the close-up the spines are facing to the right. (00:26:40)
Continuity mistake: When Homer is eating a krusty burger you can see crumbs on his face, but in the next shot of him talking the crumbs have vanished.
Continuity mistake: When Marge is in the kitchen trying to figure out the meaning of "a thousand eyes", behind Grampa there are three spoons hanging from hooks, but when Marge tells Homer that the warning in church was about the pig, the spoons have vanished and instead there are three cups hanging in their place.
Continuity mistake: When Marge is in the kitchen with Grampa wondering what "a thousand eyes" can be, over the telephone there's a notepad with writing hanging from a clip, but when Homer walks in with the pig the notepad is hanging from a string and the writing has disappeared, but then it switches back again.
Continuity mistake: When Homer and Bart are on the roof attempting to fix the shingles, Homer's wearing a tool belt around his waist with assorted tools, but when Homer shakes the antenna his tool belt has vanished (Homer's belly cannot hide that tool belt), but it reappears when Bart's hanging onto the gutter.
Continuity mistake: When Homer runs into the EPA supply shed to find something to help him climb the dome, there's a window on each side of the doorway with little space between them, but in the interior shot not only is the style of window different, the space has increased significantly and the second window is gone.
Continuity mistake: During the scene with the angry mob, knobs on the bedroom's wall cabinets keep switching between being on the left or right sides of the cabinet doors (which would also change the direction those doors open). (00:32:50)
Continuity mistake: While the Simpsons are walking the plank of wood between their house and Flanders' house, in the shot right after Plopper the pig pushes the wood plank off the windowsill, just as the Simpsons fall and the arrows fly by overhead, note the mysterious cable box and long cable that have suddenly appeared out of nowhere, attached to the wall beside the second window on the opposite side of the chimney. (00:33:50)
Continuity mistake: During the town hall meeting, on the lower floor there are two sections of seating divided by an aisle, and in every shot of the audience we see people switch seats or sections they're in, and some clothing changes as well. Just a few examples: 1) the Sea Captain's first seated behind Moe and Lenny, then he's behind Willie; 2) Krusty, Mel, and Luigi are behind Bumblebee, but the next closeup has Mel seated in front of Luigi and Bumblebee, and Krusty has vanished, but he reappears when they spit the water; 3) And in that same shot the guy behind Luigi is wearing a white jacket and purple shirt, but when they all gasp he's wearing a black shirt and green jacket. And so on. (00:19:20)
Continuity mistake: When Marge and Homer are in the backyard with the silo, there is a drawing of a pig on it, but in Homer's close-up with part of the silo in the background, the part of the silo that's visible should have the pig drawing at the top, but it does not. Later, when the silo's found in the lake, the words and drawing differ and are much lower on the silo. (00:22:30)
Continuity mistake: After Lou shoots at Bart's skateboard, before Bart flies past the truck's windshield, when we see Krusty Burger across the street (note the post and triple window), the road surface has double solid yellow lines. The double lines can also be seen when Lou scrapes Bart off the window. However, when Bart is handcuffed to the post, that same road now has single broken lines. Also note when Lou cuffs Bart there aren't any lines at all on the road. (00:12:50)
Continuity mistake: When the Simpsons are trying to escape the angry mob, as Marge and Homer get into the car, the driver's side mirror is missing from the door. Then in the next shot, the side mirror appears on the door, but now the rear-view mirror has vanished. (00:33:40)
Continuity mistake: When Homer falls onto the barbecue during the failed escape, there is a lower window at the corner of his house, which didn't exist in the exterior shot of the house, just before we see Homer and Marge watching the news about the silo being discovered. (00:31:50 - 00:34:50)
Continuity mistake: In Alaska, when Homer is holding the wood logs, the amount of logs changes from three to four between shots. (00:48:00)
Continuity mistake: At the gas station market, when Bart puts the can of soda pop on the counter, we see the yellow label on the glass beef jerky jar, facing away from Bart. When Marge points to the beef jerky its label has vanished, then when the clerk points to the similar looking family the label is back. (00:45:00)
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