While fraggles is one lucky bunny and will be just fine, we all need to be extra careful when it comes to chocolate and our own pets. Katie did a great job and got Fraggles to the vet nice and quick, she is in excellent hands. You and Jason cant blame yourselves, this could have happened to anyone, especially with a bunny as special as fraggles lol
Note
Some animals for some reason can handle eating large ammounts of it with no ill effects, but there are other cases where just a dab on the nose has been enough to kill a beloved household pet.
Ofcoarse the more rich the chocolate the more dangerous it is, but since alot of "chocolate" we eat more often out there, doesn't actually have much of any real chocoalte in it, most incidences are pretty un-eventful.
Chocolate (Cacao) is dangerous for all animals, with dogs and cats we have the ability to get them to vomit (bit of Salt and Hydrogen peroxide poored down their throat) to prevent them from digesting the chocolate and letting it get through their system. We can't do this with bunnys which makes it more urgent to try and get them to a vet.
http://vetmedicine.about.com/od/toxicology/f/FAQ_choctox.htm
If you think your bunny had ingested chocolate please contact a vet, in the case of chocolate toxicity, you dont need to worry about finding your "rabbit savvy" vet, just a vet that will see a rabbit, as the treatment for chocolate in bunnys is fairly similar to that of dogs and cats and we already know what the problem is. Phone them and explain your rabbits size, the type of chocolate they ate, and how much. They will be able to help determine if its necessary to be seen asap, for example if your bunny ate 1 chocolate oreo vs a Lindor dark chocoate bar.
Having personally spent many hours with vomiting pets in the back room of a clinic, critters eating chocolate is not a fun experience for anyone, nevermind the animal thats been effected.
This might be an excellent opportunity for us to refresh our memory with some toxic food lists.
http://www.helium.com/items/1372406-foods-that-are-poisonous-to-rabbits
http://www.3bunnies.org/poisonous_plants.htm#list