There is a bit of confusion over how the Raid Finder interacts with the Saga of Zath quest. I’d like to clear this up:
Boss Kills in the Raid Finder will NOT update your Saga of Zath Quest. Players must defeat the bosses in organic raids in order to receive credit for their Saga quest. I’ve added this information to our FAQ.
I’m very sorry that the Saga of Zath Quest is not clear in this regard. We are investigating elegant ways to make this more clear.
“To [Shaogens]: now I have a quick question
[Shaogens|Game Master]: Sure.
To [Shaogens]: are the other bosses rf bosses
To [Shaogens]: to complete saga that is
[Shaogens|Game Master]: They should be, just like Thoth-Amon, completing the raid in RF should complete the quest goal, though sometimes if you are too far away from the kill this could cause it to not update.
To [Shaogens]: got it, ok that clears that up then”
As you can see it’s not just players that are confused about this Saga RF question
Silly GM’s. Time to send them back to training!
You’re right! GMs made mistakes! 
I’m going to lock this to prevent clouding the issue though.