It happens sometimes or randomly. My partner said that my unconscious body is sliding away on its own and I can't do anything about it, but I can see myself that I'm sliding when I press "Esc" button to bring menu up, it's visible in background in light grey that your body is moving/sliding on its own, my buddy conformed it too, all the time said that I should be still so he could patch me up. When I first time noticed such sliding possibility, it was when I hit/killed some dude who tried to kill me, he started to slide up on hill, I was like "wtf", i even streamed it down, cause I was streaming back then. Once again I noticed it when server shutdown or I got shot, or I fell unconscious, I press somemovement buttons and I even stood back on my feet, all I saw that when I pressed "esc" when you can see in background of menu that I was standing, when I moved in "you fell unconscious" screen, I could see changes in "menu" screen.