CW IW doesn't stop Pos attack

Image of successful IW, and the death of the IW target

I assume IW is supposed to stop a Pos attack.

To reproduce: as CW, ice ward a target, and have a possessor possess you and attack the warded target, all on the same night.

Having asked the possessor in game, I got confirmation that I was indeed possessed to attack the target I was warding.