I think the strong torque you felt might be from the side collision avoidance kicking in as you suspected. There was a time when I was trying to pass a car from the left on a curvy part of the highway that had a wall with 0 shoulder like yours. I must have hit it pretty close to the wall, and I clearly felt the steering wheeling locking tight on its own, preventing me from turning it further. I do not know if I'd hit the wall had it not kicked in (I don't think so based on my memory of the situation), but it certainly made sure of that.