SoG is already "camped" as it were, on Chaos. He is on 18 hour respawn. Once a "group" kills him, they can predict the next time he will appear, and basically have excellent chance of farming him for up to the next several spawns, if not the entire week.
My suggestion, would be a Global serverwide message upon the death of Son of Gigaroth. "Far in the east, the mighty spawn of Gigaroth has fallen at the hands of brave adventurers!"
Then the whole server knows he was just killed, and knows approximately when the next time he will rear his ugly head. Would avoid the secretive camping mentality that happened with Umgruk. The same thing is happening all over again.
The broadcast message upon death could be used for other epic style named mobs as well.