Advance to time index 0:23:50 to see Catwoman put her milk carton on her kitchen counter and leave it there as she goes back to the office. However at time index 0:29:58, when she arrives home again the carton of milk has disappeared and is no longer on the counter. Then, you see her pull out the exact same carton of milk at time index 0:30:14.
Mistake: Wobbling tombstone
Watch the scene where the Penguin enters the cemetery to visit his dead parents grave site. As soon as he walks up to the grave, he bumps into a tombstone by his right fin side. You can see it wobble back and forth.