I'm copying this from someone else's Steam post, because I was able to reproduce it just now.
"just died a few times when i used a ladder. My char starts walking than+sholder his weapon and he falls down the roof. Sometimes he gets teleported back onto the ladder but sometimes he just dies."
I was on a roof top, with my weapon out, used a ladder, and my character just proceeded to holster his weapon while moving forward, which resulted in me jumping down the roof and dying. Since someone else had the same experience (which I found by googling), I would say this is now reproduced by me.