What is happening is (this happened to me) I got smoked into a witch, she went nuts and ran off, didn't kill me. I think they're focusing on mains, but at that point the only main alive was REALLY far away. (in the mall, on the 2nd story in the back, while the main was up by the alarm switch)
I know they used to attack anyone who got smoked into them.
Also there is some confusion as to whether or not witches that are already bought/on the map turn dangerous once it's bought. I know when we used to buy it, everyone became dangerous. Now it doesn't appear to be the case. Still sometimes it happens so fast, I'm not sure if a smoker pulling someone into her incaps them, because we know they won't kill someone incapped.