Random rare drop?

So my brother was killing some mobs outside of Maraudon and found a purple item (gloves), that, after doing some research, have no chance of dropping from the mob killed. Can anybody explain that to me? Was that just some random glitch or whatever?

Thanks <3

I lost my gloves around that area, they're most likely mine. If you'd be so kind and return them to me, I'd be willing to give you 3g 50s.

What the item? http://wotlk.cavernoftime.com/item=867 ?

It's a "global drop", every mob in a zone or within a level bracket has a ridiculously small chance of dropping them.

Not all loot tables are accurate. I have got fiery weapon pattern drop from Stratholme trash when it should only drop from Pyromancer boss in BRD