When the DVDs comes out, check the throne room scene in JEDI at the point shortly after Luke has severed DV's hand. The Emperor has just 'zapped' Luke for the first time and pauses to gloat. Look over the Emperor's left shoulder at the top of the stairs. If the picture is clear enough you should see someone dressed all in black step out and place their hands on their hips (you will only see them from the waist down). In L.A. in 1986 Maureen put me in charge of looking after Richard Marquand (bless her for her degree of trust), so I had the chance to ask him about it. Richard turned red. You guessed it. When I asked why, his response was to the effect that dressed in black he shouldn't have been visible! Bad enough I picked him out on screen. He was even more embarassed when I told him Maria, my (at the time) nine year old daughter had spotted Oola popping out of her costume. L.A.'s WorldCon that year was Richard's first (and I believe only) close encounter of the fan kind so he was astonished with how perceptive the fans were.