Supervising new divers can be stressful. I know one of my friends had a bad experience with a novice who lost his reg and panicked and bolted (rather than execute the reg recovery he had been taught, or ask to share gas). You take on a lot of responsibility when you dive with newbies. I think you handled this well, and the other diver's reactions were unexpected. Did you debrief the dive, and what SHOULD have happened?