This too, for example, raiding in Firelands in Hyjal (for transmog gear), you die in some boss, you can't return to instance because you need to fly back and you can't fly.
In blizz servers I think, in some zones like in Cataclysm zones and in Northrend, you can fly in spirit form, making returning to corpse a lot easier. But here, dying in hyjal, you need to exit game, unstuck in control panel here OR ress in graveyard with ress sickness - both ways take a lot longer than if you can fly to corpse.