Is there a word that describes someone who remains calm in arguments, even when the other side is extremely angry? For example, someone who smiles and replies to angry remarks? I thought of taunting, but it doesn't suit the situation I'm thinking of.
Example sentence: He was
even when the English teacher yelled at him, making the teacher extremely angry.
Note: It shouldn't mean calm, but more like taunting or sneering, in a calm way.