There are some changes we can make to Druusk without trivializing the encounter, to give raids a little more leeway.
I'm not saying that the adds don't go under the ground sometimes (They very well may, it wouldn't be the first time there were issues with pathing), but they do use a stealth-like ability, which could look a lot like what you are describing.
The statues and fear should never be active at the same time. Is this something that has actually happened to someone? If so it is a bug that we can address (Although looking at it, I'm not sure what would have caused the bug). Essentially the statues being activated and the fear are related events that can never occur simultaneously.
LINK
(Lyndro-EQ2) Re:Retuning in Veeshan's Peak
