There was an interview somewhat recently where someone asked his connection to Israel's military, and he squirmed and rapidly stuttered in sheer terror for about 15 seconds before he finally put together a sentence where he said something like "I'm not allowed to criticize Israel." It was weird seeing one of the richest men on earth suddenly have absolute fear in his eyes and talking like he had a gun to his back.
Twitter has since had the videos wiped, but I'm sure they're still out there somewhere. I've seen other people like Zuckerberg dodge questions, but I've never seen a man with such wealth and power suddenly become so completely terrified.