Kherab confused by druid from statue
Gives shield of raw steel for free
I kicked a statue and it produced a hostile druid monster. After killing it, I talked to Kherab for the first time, who told me to kill Guth'Alak, then thanked me for having already done so and gave me the quest reward.
I guess the check for whether you killed Guth before getting the quest is just "is there a druid on the kill list?"