He didn't answer any of the questions. He did whine that he was treated rudely, though. As for his credibility, I'd say that didn't exist before, but I was very glad to see the way he was treated.
I think he was surprised at the questions because my guess is he assumed that he'd be treated with kid gloves in the name of free speech. I guess he doesn't understand that free speech doesn't mean you get to go unchallenged. I also think you're correct that he's used to tightly managed groups of people who lob soft balls at him. But I can think of another leader who is used to the same