Dead Orcs can see

I'm in the final chamber fighting Arrok.  I beat him, I beat everyone, but I also Banished a Fire Elemental and while waiting around for ten rounds to let it just cease to exist is kind of amusing, I'd prefer to fight it.  So I'm getting everyone ready for the fight when I drop Banish, except there is a Dead orc here watching us and calling out positions.  I took a screen shot to show the orc in question and his line of site to my Ranger.