When Sherman and Roberta are snooping around in the factory, Sherman accidentally touches a button to activate a conveyor belt. However, the button he touched was clearly marked "Off" rather than "On".
When Sherman is punching buttons in the Batmobile, some of the weaponry deployed seems uncharacteristically lethal for Batman, including a bank of missiles.
When Penguin picks up his umbrella after Raven is defeated, a cell error makes it look as if there are two umbrellas.
When Sherman is hanging up the newspaper clippings, in the closeup shot, the clippings overlap each other on the wall, but, in the next shot, there is a space in between them.