Does being “reduced to 0 HP” due to failing a Quivering Palm save apply to the Instant Death rule?

@mikemearls @JeremyECrawford Does being "reduced to 0 hit points" due to failing a Quivering Palm save apply to the Instant Death rule?

— Connor Weide (@CanisCaelum) May 25, 2016

The instant death rule (PH, 197) relies on leftover damage. You failed a save vs. Quivering Palm? No leftovers. #DnD https://t.co/F5wrQRVzbc

— Jeremy Crawford (@JeremyECrawford) May 25, 2016

@CanisCaelum @mikemearlsAn odd result: a PC’s *succesful* save could feasibly result in instant-death, but a *failed* save couldn’t… Yep!

— Jeremy Crawford (@JeremyECrawford) May 25, 2016