If I Had the Wings of a Bugaloo - S1-E5
Other mistake: After Courage and Joy are free from the glue traps, there is still glue on their feet, yet they walk without any trouble.
If I Had the Wings of a Bugaloo - S1-E5
Other mistake: Joy's feet are stuck in Benita's glue trap, but she steps backwards twice before Harmony and Courage pull her out.
Firefly, Light My Fire - S1-E1
Revealing mistake: Courage winces and reacts before the stereo-zapper is fired.
Firefly, Light My Fire - S1-E1
Benita: Maybe a little torture will change your tunes!
Harmony: What more can you do to us? We've already heard you sing.
Lady, You Don't Look Eighty - S1-E13
Trivia: Caroline Ellis (Joy) references her actual birthday of October 12 when she complains the boys forgot it.