Reload an earlier save. Alterenatively, depending on where exactly it is, you might be able to jump to it. You don't need to be close to it past activating the "Press A to loot" prompt. See if you can parkour your way close enough, just smash the applicable button, and if you're lucky you'll be able to open the menu.
I dont know how falling will affect it, if at all. I've gotten plenty of shards this way, but I mostly just slide down slopes or drop a very small distance.
