players are often stuck in an incorrect/old animation loop for their character, it is particularly common when double-gunning (one gun on back, one in hands)
it is fairly easy to reproduce
get a primary gun on your back
find another primary gun
go prone near the 2nd gun
crawl-forward while the inventory screen is open, drag the weapon to your hands - keep crawling for a couple of seconds
stand up
ask nearby players to describe what they see
Whenever a weapon-switch animation begins, the server often fails to relay the ending of that animation to nearby clients, resulting in their clients leaving the player in the last frame of the weapon-switch animation indefinitely. They will appear prone even if they stand up, sprint, lean, vault - the only thing that stops it is taking the weapon out of your hands, presumably because the server relays a 'hes stopped the animation now' packet to each client.
you will now appear to be either
- prone completely still -regardless of your real stance
- crouching completely still -regardless of your real stance
- standing completely still -regardless of your real stance
you can run/sprint/vault etc and other players will see you in a static standing/crouching or prone position.
This is very-bad for the game because of the way the server trusts the client.
If i am STANDING-BUGGED, but on MY SCREEN I am prone. Other people will see me standing, and can shoot my standing represenation of my (actually) prone body, and the hit will still register.
We show this on stream all the time, when I am prone bugged I will get someone to punch the standing version of me that they see, and on my screen they are punching thin air - but I take the damage or become knocked out.
This also effects players in the opposite manor, if you are prone-bugged, appearing prone to everyone. You can spring around and fire your gun, but people will only see a prone player sliding around the floor moving at sprinting speed. This means you can run up to people and attack them they they wont have a clue what is going on.