I kind of thought that was inappropriate also.
I mean this is one of his supporters talking to him.
Not sure if it was arrogance or ignorance.
My kids used to do that when they were teenagers ... anytime I had them dead to rights ... I kinda think it was nervousness as well as arrogance. What he really wanted to say to her was "whatever" and move on to the next question. Besides he is not good without his teleprompter ...