When Homer first encounters the traffic jam there are no bodies on the road. After punching the drivers head off the floor is now littered with dead bodies.
In "The Homega Man" when Homer is escaping from the mutants in the hearse, in the shot when he steers the hearse into his driveway there is no sign of the mutants behind pursuing him but in the next shot as Homer escapes into his house the mutants suddenly appear onto the Simpson's driveway as he rushes inside to take cover.
At the beginning of "Easy-Bake Coven," when they are about to perform the witch burning, Ms. Hoover is tied to the left stake and Ms. Van Houten is tied to the right stake. After Mayor Quimby accuses them of witchcraft and orders them to be burned, Ms. Van Houten and Ms. Hoover switch positions.
Flies do not eat sugar they eat rotting materials, they do not produce suitable enzymes to digest it. Flies going near soft-drinks, etc, is more to do with colours and odour from people.
Ironically, the Simpson family survives the neutron bomb attack due to the abundance of toxic lead paint in their home. In reality, while lead provides an effective shield against several types of ionizing radiation, it does not absorb the neutron radiation released by such a weapon.
In "Fly vs. fly", when smoke leaves the machine while it is in the Simpson's kitchen (just after Bart and the fly are mismatched), Homer's hand appears to be transparent, as we can see the line of the pod door through it.