Casting Doubt

sorcerer Vutral seems to have an longer then usual spawn timer, as of 1/5/211 waited for 7 minutes and when i came in the corpse was not there either, just wait he will spawn

If you see his corpse you may have a 10 Minute Spawn Timer wait

If you dont see his corpse will be less than ten mins

Sadly the only option is to stand your ground and wait for the npc to spawn

When he speaks in chat :

Your.....Betrayal....Will....Be....Revealed, ( you are looking at about 3 mins spawn time )

If you're doing the Necrolord campaign and using Balmedar's disguise, do not complete this quest. The disguise drops when you go into combat and there's no extra action button to replace the disguise afterwards.
Ignore this and read my edit.

Edit: Having now done it again on an alt I have discovered the following; If you complete this quest just prior to going outside to kill Kel'Thuzad for The Traitor Unmasked, Balmedar helps you to kill Sorceror Vutral. Also, the quest reward [item=183397] returns your disguise.