OP: In some quests, my mouse pointer is automatically directed to hover over the "reroll loot" button. I move fast through quests and am used to automatically clicking - so Turbine, b/c of their lack of a confirmation dialogue box, dishonestly took my shards once. Now I move my mouse in any direction away from the chest, so that I don't click on that stupid, shard stealing idea.
However, I submitted an angry bug report and was rewarded with a like amount of Turbine Points. So while I continue to feel that not having a confirmation box is dishonest, I'm impressed they would return the shards in the form of TP.
I strongly recommend you write them and demand your shards back.