Why are the subjects of congressional hearings so submissive at these hearings?
Take the recent US congressional hearing with the CEO of Google. I found Sundar Pichai extremely patient, calm and even timid in his responses even when faced with idiotic and sometimes rude questions. For example, here by Ted Poe.
Is there anything stopping him from calling out Poe's question as stupid for expecting a yes/no answer to a very complicated question? Moreoever, he gets repeatedly interrupted and this is clearly a politician trying to score a zinger, as opposed to someone trying to work with Pichai to get to the bottom of a complex issue.
This even applies when politicians themselves are the subject of the hearings - e.g. Hillary Clinton, a seasoned politician, was equally deferential and courteous at her email scandal hearing while her questioners were the diametric opposite. Why is this so?