So, if I have a long flight on my druid I usually alt-tab to Allakhazam, like this, to post. Well, I went back to the game and found myself dead.
From fall damage.
Apparently if you fly into a mountain, the game puts you back at epic land mount speed, and if you go over a ledge... you splat.
Very odd bug. Just thought you might want to be careful while scrolling Allakhazam ;-)