Yer duct tape probably aint the best of things to stick to a plant but hey if it works its all good.
Plants heal very well from breaks and snaps, as long as the water and transport system aint severed then it will heal no probs. I always worried when i snapped a branch off completly but they always stick back on if your quick and support it whilst it heals.
Plants like a bit of abuse, not always a bad thing the odd snap or break, takes a lot more than that to stop a weed plant growing, bolt of lightning or act of god but other than that they are a hardy species. Peace