He made a bunch of misplays in the Druid game before that but yeah, his Priest play was solid. Probably nerves and lack of experience with the class because those plays were pretty simple and Druid in general is pure babby mode.
Why did he burn a swipe on that Doomsayer instead of just Silencing it? That play made no sense to me. Freeze mage doesn't really have anything that can buff a 0 attack minion?