Pretty situational but I consider a very minor exploit anyways. This only involves using blizzards own questhelper and only work on certain quests. I used this exploit on Dreadsaber Mastery: Stalking the Prey - Quest - World of Warcraft
https://i.imgur.com/HqOfR.jpg
Notice the tooltip. It only says "Dreadsaber Track"
https://i.imgur.com/feInU.jpg
Notice the tooltip again.
What happens when I loot the track in the first picture
https://i.imgur.com/JMJ72.jpg
What happens when I loot the track with more complex tooltip
https://i.imgur.com/FZk8H.jpg
If you find or know any quests that have a similar mechanic then please report those quests in this thread.