I coudl see drugging a fish due to the fact that they have a brain and some level of 'reasoning' (for lack of a better word) beyond a reaction to a direct stimulus. Corals lack a CNS and do little (if any) more than plants when reacting to a stimulus. They take to shipping much like I'd imagine they take to a storm or a rock getting knocked over in a reef. It would be the chemical and thermal changes that kill coral. A fish can stress and die from those factors, plus 'understood' stressors, like a change in environment.
I use a scalpel when fragging. I cut the mat and then carve some of the rock under the polyps. It's hell on the blades, but better on the coral IME.