Why didn't Durkon Plane Shift to Celestia to talk to Roy?

[littlebum2002]

"Precise accuracy as to a particular arrival location on the intended plane is nigh impossible. From the Material Plane, you can reach any other plane, though you appear 5 to 500 miles (5d%) from your intended destination" and Durkon didn't even really know where exactly his intended destination was? Celestia's bound to be huge.

I guess "whever Roy Greenhilt is" isn't an accurate enough location to base your arrival at lol