Continuity mistake: When Homer dumps the silo, in the overhead shot as it sinks, the car is parked right at the shoreline, then as the pollutant spreads in the water the car is much farther up on shore. (00:23:05)
Continuity mistake: We see the interior of Homer's car twice, first when Homer is at the Hazardous Waste Treatment Center, and then again when he and Marge are trying to escape the angry mob. The dashboard and steering column are entirely different both times. (00:23:20 - 00:35:20)
Continuity mistake: When Homer heads to the lake to dump the silo, the car's rearview mirror disappears and reappears. (00:23:50)
Continuity mistake: The one eye by the back leg of the squirrel keeps disappearing and reappearing depending on the shot. (00:24:25)
Continuity mistake: When Bart and Ned find the mutated squirrel, two EPA workers find the creature. When the female worker says "Environmental Protection Agency" after Ned asks who they are, the squirrel is standing on a rock with nothing under it. In the next shot, there is suddenly something under it for the EPA worker to contain it with. (00:24:30)
Continuity mistake: After Russ Cargill goes through the eye security system, in the overhead shot as he enters the Oval Office, we see the Seal of the President (on the rug) centered between the two couches, and there are two red chairs behind each of the couches. However, when Cargill holds up the tank with the mutated squirrel, the large round Seal is off to the side of the couches and one of the chairs is gone from behind the couch. (00:24:50)
Continuity mistake: When Russ Cargill holds up the tank with the mutated squirrel to the eye security system on the wall, there is a square piece under the handle to secure it to the top. However, when Cargill holds the tank up to the President that square has vanished and it's just the handle. Then when the President is face-to-face with it, a bar has appeared between the two sides of the handle. (00:24:50)
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 provides the President with the first set of five options and spreads them across the desk, the handle on the mutated squirrel tank is perpendicular to the president, but in the next shot the handle has flipped around and is now parallel to the president. (00:26:10)
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: After Russ Cargill places the tank with the mutated squirrel on the President's desk, when Cargill says, "Here's our chance to kick some ass for mother earth," the tank's not on the desk where it was placed, but then it reappears where it should be. (00:26:10)
Continuity mistake: When the dome is being lowered over Springfield, The amount of choppers carrying the dome changes depending on the shot. (00:26:20)
Continuity mistake: When the dome is lowered it is done so by 100s of helicopters that release the dome as Homer runs outside. The camera zooms out to show the whole dome and the helicopters have disappeared instantly. (00:26:20)
Continuity mistake: When the dome is being placed over the town, the church and Moe's Bar are shown right next to each other, but later on in the film, when Barney runs out of the Alcoholics Anonymous meeting at the church, Moe's Bar is nowhere to be seen. (00:26:30 - 00:48:30)
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 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)
Continuity mistake: After the dome is placed, when the Simpson family runs out the back door of the house and Homer shouts, there is only one window on the second floor, above the back door. There should be two windows. The light fixture on the wall beside the door is also gone in some shots. (00:27:40)
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: A wood appears outside the Simpsons' fence when the dome has been lowered. (00:28:00)
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)
Answer: I believe the joke is supposed to be that the way Texans speak is a language all its own.
Damian Torres