Rare sense and drop luck shenanigans

My priest tends to have all sorts of ridiculous drop luck.  This has always been the case for her, even while she was leveling.  I've never had such a lucky character!  Unfortunately, the troll instances haven't been too terribly kind to her since it was decided that she's going to be raiding again.  This has been baffling for me - she always has good luck.  What was going on?

Today, I found out.

I was getting Tol Barad dailies done, working toward the spirit trinket.  It was the much-hated quest to kill 12 spiders.  Killing quests don't bother some people, but I get cranky at having to kill a decent number of mobs, since I tend to pick them off one at a time so I'm prepared in case someone jumps me.  I hadn't gotten more than three spiders in when I found myself off to the side with no target spiders around and a lone fox.  I took one look at that fox and knew it was going to drop the minipet fox.  Mind you, Kalliope had never had luck farming for that thing, so I had given up looking.

So I kill the fox, and sure enough....

Typical.