Continuity mistake: The lead singer of Green Day disappears in the shot from behind the drummer's back - he is nowhere to be seen, even though where he was standing before means he should be visible from that angle. (00:03:20)
Continuity mistake: When the Alcoholics Anonymous run out of the church, Barney yells out "I can't take another minute in this dome!" and charges towards the dome. In the overview shot, the church is directly behind Barney. In the following shot that shows Barney hitting the dome, the background has changed completely. The church is no longer there and two houses have suddenly appeared.
Continuity mistake: After the Alcoholics Anonymous meeting runs out of the church, Barney starts yelling and a huge crowd is visible behind him. Bumblebee Man is standing a few meters away from Barney on the end of a row. Next shot, Otto and Moe have suddenly appeared next to him as well as a huge crowd.
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: Throughout the movie, the exterior side wall of the Simpsons garage changes length significantly, even between shots.
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: 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: 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: 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: When the silo is pulled out of the lake, Eddie is writing in a notepad. However as the silo turns round he has his arms crossed. (00:30:50)
Continuity mistake: Russ Cargill puts the 5 options on the desk the first time and spreads them out. His hand is then covering the number 5. Camera changes to another angle and his hand is no longer covering the number 5. (00:26:10)
Continuity mistake: When the dome is lowered we see Sideshow Mel hitting it with his bone. In the background you can see Dr. Hibbert and his wife. When Russ comes on the dome, Dr Hibbert and his wife are now in a completely different spot, and have changed sides. (00:28:00)
Continuity mistake: When Homer drops the bug zapper in the pond, we see he still has the wire in his hand. Camera cuts to him about to grab a fish and the wire has gone. (00:16:45)
Continuity mistake: When Krusty is filming the advert for the Clogger, before the director says action the bin is to the side of the set with a boom mic stand right next to it. After the advert, the boom stand has gone as seen when Krusty throws the burger away. The bin is also closer to the curtain than it was before. (00:14:05)
Continuity mistake: The clipboard Colin has when he first meets Lisa vanishes from his hands. (00:10:20)
Continuity mistake: When we see the news report of the silo being lifted out of the lake, the height of the silo has significantly decreased, compared to when it was in the Simpsons' backyard - note the empty space below the drawing of the pig. (00:21:30 - 00:30:50)
Continuity mistake: When everyone approaches the edge of the dome, a group of police officers arrive. As Chief Wiggum says "open fire", he is standing in front of the officers. In the next shot, Wiggum and the officers are standing even with each other. (00:27:40)
Continuity mistake: When the dome is placed over the town and Marge says "Trapped forever, it's all coming true" we can see a hose on the garden tap in the background. But a couple shots previously we could only see the garden tap but no hose. (00:27:10)
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