When singing his solo in "We're Sending Our Love Down the Well," Rainier Wolfcastle is not wearing a holster. When the shot changes to depict the entire group, he is suddenly wearing a holster over his left shoulder.
When Krusty is in the tunnel hammering in the spike it is barely the size of his hand and is sticking out of the rock unsupported. In the next shot it is much larger and takes several characters to hold it in place.
At 6:14, Bart's right ear is missing.
It was said not one cop on the whole force was thin enough to go down the well however Lou and Eddie both were thin enough to.