Dizzonner the Penguin (2) - S2-E18
Other mistake: In the fight in Convention Hall, when the goons surround Batman, watch the one on the front left. He's punching over and down, yet he's hitting nothing.
Dizzonner the Penguin (2) - S2-E18
Other mistake: Batman throws himself into acid. Counting on acid-proof suits, Batman comes out unscathed, but his ropes didn't get burned off until he dipped the back into the acid. Also, even though he covered his face a moment, he came out with his face exposed, and undamaged, when it should have been burned.
Other mistake: At the end of the episode when the cattle are stampeding, the sign over the Saloon is backwards.
The Duo Is Slumming (2) - S2-E32
Other mistake: While Batman and Robin are ascending in the balloon, Robin picks up a chewed piece of gum, and stops the altimeter just before 20,000 feet. After that, Robin wondered how to get down. Beside Batman's head is the handle of the cord that would have started to let the air out, and started dropping them down.
Pop Goes the Joker (1) - S2-E57
Other mistake: Not only can Caesar Romero's moustache can be seen, but the line between the white makeup and his skin on his neck. Also, when Robin's face came out of the clay, his mask was almost around his mouth. A moment later, the mask is back in place. Later, his face, mask, and body is spotless.
Surf's Up! Joker's Under! - S3-E10
Other mistake: An amazingly precognizant Dick Grayson is already wearing his surfing togs before Commissioner Gordon calls to say that Joker has invaded the surfing community. (00:04:30)
Suggested correction: Dick isn't amazingly precognizant. He's wearing swim trunks while using the rag to prep his own surfboard. Barbara Gordon was already at the beach with Skip, and Dick is heading to the beach with his surfboard as well (00:04:34).
The Funny Feline Felonies (1) - S3-E16
Other mistake: At the start of the episode, Bruce Wayne and Warden Crichton are overseeing Joker's release from prison, but at the tail end of the last episode, Batman is shocked that Joker is released from jail. He could not be two places at once.
The Joker's Flying Saucer - S3-E24
Other mistake: Just before the final fight scene, Alfred hits his head on the door of the spacecraft while exiting, kind of like the Storm Trooper in Star Wars, reacts for a second and then keeps going on with the scene as if nothing happened.
