Yeah, i've had that happen too, there are a few possibilities.
1. The body will eventually adjust the level slowly and it will go away, simply because it has enough energy stored up to restore the balance. Over time, though, if you keep eating bad it will progressively lose the energy it needs to restore it and you'll take a long time to get better, maybe even days.
2. Whatever you ate may have caused a sharp drop, but may have also contained enough carbohydrates to restore the level a bit at the same time that it dropped it. The drop may have happened, but you can't forget the fact that there are carbs there, regardless of how bad they may have been. Of course, as I said in number one, the same issue applies over time.
3. Your regulating mechanisms may not be entirely messed yet.
4. Your hypoglyemia may not be as severe as other cases (thus you may be able to handle grains).
5. It may simply be a coincidence and a sign of bad things coming. The restoring of the level may simply mean something is wrong, but it's not that bad yet.