The Chaos Patrol in cata Convocation, the one in front of the first gate you have to open, which leads to the elevator, was balled to a hedgehog, while chanting, not doing a single step.
You have to trigger them to continue the mission. Happened two out of two times the patrol spawned at that location.
The Chaos Patrol at the very end of cata Empire in Flames, close to the last tome, spawns triggered. You come in range to hear the chant, and a split second later you hear the triggered shout and followed by the noise of heavy metal rushing towards you. Also happened twice in the last couple of days.