When Homer is at Moe's, there is a car in front of the tavern identical to Homer's sedan, but it is purple instead of pink. It's unknown if it is a coloring error or another person's car.
Chief Wiggum tells Homer to do Sarah's hair for the policeman's ball that night. However, several scenes later we see the daylight sky while Lisa is following Milhouse and Taffy before the policeman's ball.
A flashback reveals that Homer brushed his own hair out as a teenager; however, "And Maggie Makes Three" shows that Homer tore his hair out when Marge was pregnant with Bart and Lisa.
Leading into that flashback, Homer says that being able to cut hair is a natural talent he acquired due to losing his own and not wanting others to feel the same way he did, yet in "A Milhouse Divided" he attempted to style Marge's hair and it looked terrible.