Seriously Max (my dog) you have some major food thievery skills.
My dog is the ninja of table scrap acquisition. He also has an iron stomach. Oh, and he can suck food out of openings vacuum-style. You would be impressed!
His latest is a chocolate Halloween cupcake that I thought was long gone. I found him chewing apart a ball of foil this morning and that is the only possibility since I haven't had anything else wrapped in foil around here in the recent past. I figure it didn't get eaten today, only revisited so I am not too worried about the chocolate thing. In the past he has eaten a dozen brownies, seemingly extracted from their individual plastic wrappings by said sucking method since the folds of plastic were still perfectly intact. His sweet tooth also had another cupcake episode wrappers and all one Fourth of July, though he left the toothpick flags undisturbed :) Like I said, iron stomach.
But- it got me thinking and I decided to revisit the topic of chocolate being bad for dogs. Here is what I find worthy of passing on, compliments of About.com:

Theobromine, a component of chocolate, is the toxic compound in chocolate. (Caffeine is also present in chocolate, but in much smaller amounts than Theobromine.) Both Theobromine and Caffeine are members of a drug class called Methylxanines.

It turns out that baking chocolate is worse than milk chocolate and that for a dog of Max's size, he/she would have to consume 9 oz of milk chocolate to get an effect. I don't know about you, but I am not good at predicting ounces...... It can cause vomiting, blood pressure increase, muscle spasm and rarely, death. Scary, but then again, he IS a ninja dog so he can probably handle it :)