Your body main job is to keep you alive. If it perceives you are low, it will signal the liver to convert stored glycogen into available glucose and raise bgs. The problem with a lot of type 2's is that the signals sometimes get messed up. So even though we are normal - high bg we still get a liver dump.
although it does kick in when you're geniunely low too.... I can tell I've had a hypo when I wake up and my BGLs could be sitting between 4-5 or higher. But if I wake up between 2-4 am that's when my BGLs can be at their lowest. Having a hypo, you get symptoms and I notice it getting the liver dump obviously makes hypos a bit slower to recover from.
I read the info in the link moon provided. Now I understand. I normally take my FBG first thing in the morning even before I've had my coffee. There's been o sign of LD so far, but I haven't done anything but stagger about 20ft into the office and test. It's very possible that as I have my coffee and wake up that it occurs. When I test my breakfast I don't test directly before eating. I use my FBG reading If I indeed had a LD it could certainly explain my screwed up readings and I would have o idea it hapened.
From reading the link it also sounds like it my be a good idea to get some protien bars for a bedtime snack.