All Bungie needed to do to fix it was check if the rune is in your inventory when the button timer finishes (it already does it when you start holding down the button). Checks like this should happen on any of these "timer" events for any item, which is mostly unique to Destiny in my experience. Easy fix; from what I've read, Bungie's code is so spaghetti'd up it's difficult to make simple fixes like this (or they're just dumb).