Damn, that unfortunate. Same thing happened to me a couple weeks ago with a clone, but when I say it was destroyed... Burnt to a CRISP. One good thing about nature, it has some pretty crazy regenerative properties. I snapped two branches almost the whole way off my white widow while low stress training with metal craft wire instead of rope. (Now I see why they use rope.) I tapped the two branches and about 4-6 days later they were completely healed back to the plant. As long as you didn't burn a huge amount of the plant the rest will grow and you'll beable to harvest eventually. Also It was also a good decision on your part to cut the burnt area off. I believe the plant uses more energy trying to repair itself and if the area is to far gone you're just wasting energy that could be put into new growth.