Well Bucky's opinion of Aang's world just dropped a couple more notches.

"They blamed you for something you didn't even do?" they arrested and tried a twelve-year old kid for a crime a woman did hundreds of years before. They sentenced him to death. Yep, it says something regarding Bucky's priorities with Aang that that's the part he gets hung up on. "What the hell was wrong with them?" he growls.

If you asked Bucky he'd say that Aang should have left the people of the town to the mercenaries. "They didn't deserve your help."