When Lou walks into the water to retrieve Cheif Wiggum's sweater, he walks a fair way out until he becomes fully submerged under the water. But the police car which was pushed into the water beforehand didn't go out nearly as far as Lou walked out, yet it managed to becomes completely submerged.
Blob-Homer goes from having his normal yellow skin to having a light green glow to being completely green only to be yellow again by the end of the first segment.
The number of villagers outside the Rabbi's house varies greatly between shots.
Most of the school kids are gathered on and around the basketball courts, in the panned out shot of the school grounds, But in the very next shot, when Bart's walking up to the school bullies with the Golem, they're now all gathered around on the grass.
The Golem's towel and shaving blade mysteriously vanish when Lisa confronts Bart.
At one point we see students in Mrs. Krabappel's class listening to the "War of the Worlds" broadcast. However, the actual program aired on October 30, 1938, a Sunday.
The police car that chief Wiggum orders to be pushed into the lake seemingly levitates over the water for a split-second before sinking.
In 1938 Springfield, Chief Wiggum references "The Great Gildersleeve", a program which didn't premiere until 1941.
The segment set in October 1938 begins with Lady Day's recording of "Gloomy Sunday" which she did not record until 7 August 1941.
The Golem is holding a Winchester rifle which was not available in the 17th century.