When you come into the inn from the front door you are not far from the bar and the light is very well there. If you tried to sneak into the shadows from there you would just kind of look funny as the shadows are mostly at the back of the room past the tables in front. The customers watch as you walk around and even Durgan will see you as you walk the edge of the room. Once you get to Durgan you can great him.
At some point Zork gets up, readies himself after a bath and enters the tavern looking to see if Durgan is there and waiting. If he sees him he will go over to him and starts mentioning his dream.