Did you test after your binge to see where your bloods went?
As chocolate has quite a bit of fat, the rise evidenced can be quite slow, but long, if you understand what I mean. If, however, you did go high, there is often a responding, rebound low to accompany it. If you imaging gently throwing a ball in the air, and catching it on its way down. After a while, you can do it again, and again, and again, at it becomes predictable. (The impact of your pancreas/insulin is what does the catching in this example.)
Where you load up with more energy in the chocolate, whilst the rise might start more slowly when it goes up and reaches it's peak, when it starts to fall, it can happen quickly, catching your pancreas/insulin on the hop on the way. When the curve isn't caught, it can lead to a low. This may or may not explain what you have seen.
One thing of note though; due to the addictive nature of carbs, it is quite common, after a binge/blow out that carb cravings increase for a few days. Your body is effectively remembering "the good old days" and wants more. Try not to give in, or there is a danger of creating a roller coaster situation that can be tricky to break.
Back on the wagon girl!