Occasionally when a monster decides to use a teleportation wand as a defensive item, and the level is not non-teleport, it decides to zap you instead of itself.

Breaking a wand of teleportation will teleport as many monsters around you as there are charges left in the wand, always including yourself.

Monsters can defensively zap you with a wand of teleportation if you are not on a non-teleport level.