Aunt Harriet tells Chad and Jeremy that tea is served every afternoon at Stately Wayne Manor, before offering them cream and sugar. Someone who takes tea every afternoon, prepared by a first class English butler, would know that tea may be served with milk, but never cream.
When Catwoman has one of her henchman place a call to Commissioner Gordon, he hands her the receiver upside down, to which she unknowingly puts to her ear to talk.
When we first meet Benton Belgoodie, he is dismissing a woman saying, "We have no need for Magyar folk dances", and he pronounces the word "Magyar" as it is spelled. "Magyar" is the native term for "Hungarian", but it is pronounced "mad-yar". Someone who knows enough to refer to things Hungarian as Magyar would certainly know how to pronounce it.