I do not know how certain cc is supposed to work, so I do not know if this is a bug.
I was farming with my Ars/Ars Dom on the asteroid. Tank taking care of everything and I was hovering above him, invisible (cloaking device), doing nothing.
I decided to toss out a sleep grenade on a group that was outside of Tank's taunt range (they were throwing boulders at tank). Soon after I did that, they threw their boulders at me and killed me.
Then I tried the same thing, but with Smoke Canister. Same effect.
Are those powers supposed to cause aggro? I assumed it was passive (like Illusion's Confuse) and MOB would ignore me.