If a climber or a slider is facing left and passes through a permanent skill remover, they will be embedded in the wall.
(For clarity, since Sliders turn: the slider would have been traveling right before transitioning to slider: that is, this always occurs when the skill is interacting with a right-facing wall, thus lemmings interacting with the wall are facing left).
The object works as expected when lemmings are facing to the right.
Fixed in commit 46f7128.