Welcome to the forum, Snydley!
No, you have not made a mistake, nothing to gain except experience points there.
Spoilers (for those who did not complete Watcher's Keep)
-
-
-
-
-
-
-
Actually you've made rather wise decision since Eldrod definately deserved to go there himself for his shameless lie. It was me who made a mistake - I used the Scroll given by Eldron
. And... I was not pleased to realize that the party had been tricked
------------------
Tanda,
with best regards from Guild of Assassins