Sure, imagine that whoever killed Draco just did it by cutting off his legs. He would die, Dumbledore would arrive, and catch him. No way to avoid it—Dumbledore can use the time-turner to watch the murder.
The point of evading the wards isn’t to ensure the success of the hit, it’s to make sure that nobody hears about the death until the six-hour limit hides the murder.
Both Hermione’s death and the complex setup used to kill Draco are consistent with wards that respond only to death.
Chapter 79 says clearly : « The clear intent of the Blood-Cooling Charm had been to kill Draco Malfoy so slowly that the wards of Hogwarts, set to detect sudden injury, would not trigger. » So… why didn’t the wards detect “sudden injury” when Hermione legs were eaten ?
Sure, imagine that whoever killed Draco just did it by cutting off his legs. He would die, Dumbledore would arrive, and catch him. No way to avoid it—Dumbledore can use the time-turner to watch the murder.
The point of evading the wards isn’t to ensure the success of the hit, it’s to make sure that nobody hears about the death until the six-hour limit hides the murder.
Both Hermione’s death and the complex setup used to kill Draco are consistent with wards that respond only to death.
Chapter 79 says clearly : « The clear intent of the Blood-Cooling Charm had been to kill Draco Malfoy so slowly that the wards of Hogwarts, set to detect sudden injury, would not trigger. » So… why didn’t the wards detect “sudden injury” when Hermione legs were eaten ?
Which brings up the question: has Dumbledore use his time-turner to observe who let the troll in?