Holy **** I have no idea how the other two completely missed the focus of the post. It has nothing to do with "that's an 83 not a -83" or "well were you actually in RDF?" I don't know what's going on but to clarify for those less understanding people...
From OP's screenshot the loot system was need before greed. With the NBG loot system, there are item restrictions pertaining to your class. Example, life blows on my resto shaman that I'm leveling because I can't need on cloth or leather healing gear, even it is an upgrade. Also with the NGB system there are some items for which you cannot roll need. Example, you cannot "need" a frozen orb. It doesn't matter if you're in RDF or not, NBG rules are NBG rules.
So the strange thing that's going on is in two instances these restrictions were broken. A mage was allowed to roll need on a shield (an item a mage cannot wield), and someone was allowed to select need on a frozen orb (not supposed to be able to).
Maybe it's a bug, maybe people are doing something shady.