But I thought he was asking why it happened in the first place. I really do suspect something like the scenario I described above, where the xmas bulbs at the left of the frame gave him clipping in the histogram and fooled him into underexposing. Not a camera issue, but an operator error. It's easy to see how that could happen. They're not even in the room, and there's the white shirt and flags to protect from clipping. Who'd notice the xmas bulbs outside the window?