Spells: NPC DoTs remain after cure

[Comapavik]

I was soloing a Froglok Yun Shaman in Trakanon's Teeth, and he cast Venom of the Snake, a poison based shaman DoT spell on me. I cast Counteract Poison on myself, and the DoT was removed from my buff window, but I didn't realize until too late that I was still taking damage. I took several ticks of dmg after I cured myself, and I actually died from the dot, even though it appeared to be gone.