Continuity mistake: Before Eddie drives his Plymouth into Toon Town, he breaks out Yosemite Sam's gun for the occasion and loads it with the animated bullets. The gun starts off in his right hand. But by the following shot when he gets ready to take a swig of Wild Turkey, it has instantly switched over to the other. (01:09:05)
Continuity mistake: When Judge Doom is melting and is just about to die, the wide angle shows he's surround by a very thick cloud of yellow smoke that keeps us from seeing his face, then in the close-up it changes to a very thin smoke that allows to see his face, and then back to the wide angle and the thick smoke again. (01:31:55)
Continuity mistake: Roger and Jessica are safe when the spray-machine breaks the brick wall. It then goes through the other side staying on the left side and moving far away from the debris. Angle on Valiant, and when back to the wall the machine has suddenly moved several feet to the right and is crossing the wall again.
Continuity mistake: In the scene where Valiant leaves Maroon's office, he goes outside and closes the door behind him all the way. Then a cartoon character passes him. Notice the character opens the door by pushing on it instead of turning the knob? I thought Valiant closed it all the way. (00:08:45)
Factual error: In the bar scene where Judge Doom is looking for Roger, there is a pinball machine that can be seen on the right side of the stairs as Roger and Eddie are running out of the bar. Electromagnetic pinball machines of this design were not around at the time of this film's setting. The pinball machine is a Gottlieb Hurdy Gurdy (1966) model.