He isn't just losing hands, he is losing everything below that point, you just can't see it because his shorts and shirt are different sprites layered above his body sprite. You can try to cause the bug when Torulf is naked and you will see it.
Have you updated your video driver? If you did and the game still does that - upload your log somewhere and link it here. It's generally considered VN developer's responsibility to report to Tom all the Renpy bugs found in their VNs.
Or you can report it to the Renpy github yourself, if you have a git account or don't mind making one. https://github.com/renpy/renpy/issues