Bingowings said:
He is clearly sacred of Vader, I remember the last time I saw it in a picture palace and some little kid near me said something along the lines of' "Look he is sacred of Darth Vader...Why?" and his dad (presumably) whispered, "yes Vader is scary even to the other bad guys".
Obviously the kid didn't get the scene. He probably didn't even get what exactly the dialogue was about.