If a PC uses Shield Master to try to take half damage, does he use his Reaction anyways?

@JeremyECrawford If a PC uses Shield Master to try to take half damage from a Dex saving throw and fails, does he use his Reaction anyways?

— Devin Cutler (@devincutler) May 24, 2016

You use the third benefit of Shield Master when you succeed on the saving throw. #DnD https://t.co/llC6kxDkvB

— Jeremy Crawford (@JeremyECrawford) May 25, 2016