Continuity mistake: When The Joker's going down the garbage chute he's riding down on his butt yet somehow he's on his stomach after a shot of Batman is shown.
Continuity mistake: Captain Clown gets pressed into a block of scrap metal. The ascot faces the front side (the one facing the direction the conveyor belt carries it to) in the first shot, then Joker dumps more junk on Batman and goes away sitting on the block; the ascot is facing now the back. (00:17:15)
Continuity mistake: The boat with the gas-emitting garbage goes past the bridge, and its odor approaches the bridge trailing behind, from the left of the screen. A few seconds later it also intoxicates the street workers, but the miasma approaches from the right. (00:02:00)
Continuity mistake: Captain Clown chases Batman with its arms outstretched, except in the long shot with the crane; he is walking with his arms down his sides. (00:15:45)
Continuity mistake: When Captain Clown lifts the drum to toss it into the river, the lid shows no holes; Joker punches a few in it earlier. (00:11:55)
Revealing mistake: When Alfred proudly shows the sketch with his joke, the top part of the shower pipe disappears in some frames. (00:03:15)
Continuity mistake: Bruce's robe goes from a light purple to mint blue while he's talking to Alfred at the end of the episode.
Other mistake: Batman's lungs have plot armor; he has all the time to put his mask on even after exposure to the gas, and he reacts to it coughing at first. Nobody else in the episode reacts with a cough. (00:07:55)
Character mistake: Batman's computer warns him about the "air born gas emanating from river front district." It's airborne, and riverfront. (00:07:10)
Other mistake: At the beginning of the episode, the truck of the "Gotham Globe" delivers to the newsstand a nice bunch of copies of the newspaper, which naturally bears the name..."Gotham News" (00:01:20)
