What you are describing here is how the game behaves if the friendlyfire is off, even tho you are claiming its on, you still should provide some proof. We cant just take your word for it and yes, telling us that you changed it in config.cfg/server.cfg isnt a proof. Check serverbrowser (if your server is visible in list) or type "cvar_set ffire" in console if you are an admin (not sure if its the right way to check).
Is the direction really random? AFAIK, if you had ffire off it would bounce in a direction oposite to the angle you were aiming at your teammate and the less to the center of the model you fired, the more it would bounce to the side.
