Continuity mistake: When the doctor places the items that come with the Dimoxinil on his desk, he places the scalp massager next to the pad. When Homer asks the doctor how much, we cut back to the doctor and the scalp massager is now on the pad.
Continuity mistake: When Homer gets mad when Carl calls him "Chrome Dome", there is a fish stick on his plate, but in the next shot, the fish stick has disappeared.
Continuity mistake: When Homer is speaking to Carl and Lenny at the coffee stand, there is initially nothing in Lenny's cup, but a few shots later his cup is now full without him filling it.
Continuity mistake: When Homer is rolling around on the grass outside the house with Bart, Lisa, Santa's Little Helper and Snowball II after the hair formula works, Snowball II is drastically larger than usual in the overhead shot.
Revealing mistake: While Patty tells Selma "Look who's talking" after Homer debuts his new haircut, both of their chests up to their necklaces are the same color as their dresses. Selma's dress also suddenly has sleeves on it.
Revealing mistake: When talking to the doctor about using his health insurance, Homer's hairline above his ear vanishes in a shot then reappears.
Continuity mistake: When Homer and Karl are selecting a suit, just after Karl says none of the suits are to his liking, Karl's tie changes from green to red.