Well, in my replay, once I dismember further, my body proceeds to spin and move without interaction, you just rip yourself apart. Not to say you weren't paying attention to the replay, but you seem to have missed the point of the post.
ive always had the impression that while pulling joints doesnt break them, it makes it a lot easier to break them with an impact. in this case, you pulled your legs and hit the ground, making the legs break. it barely makes sense but it seems to be true most of the times