I don't know if it the same thing I saw, but severral times, players where "crawling" ans still moving at normal speed. I do not see it like player where swimming, so don't know if it the same probleme.
I thought it was a "setting adjustement, since there seems tobe a lot of those tweaks on RTCW.
I also wonder how are you supose to aim at thoses players. After a few personal encoter with a "crawling" ennemy, Im having the impression you need to aim at them like you would do normaly.(I have spend a full clip of ammo on the head of some allied player who had his head, torso, arms... at the height of his knees

)
So is this a glich of the game or a tweak that just a few players know of?