Ezra scowls at being called out on his lie. More than that, though, his temper sparks at Garth'zel talking about how his parents would feel. (Maybe partly because his conscience twinges a little because Garth'zel is right.)

"What do you care?" he says hotly. "It's not like it matters to you if I've got parents." Other than the fact that Ezra had tried to pick his pockets, but he'd stopped Ezra from doing that anyway.