It is common for certain mods to migrate from the servers to your computer. They will show up in other multi-player matches and even in single-player. Usually a steam restart fixes it for me.
This is one of many reasons I hate server side mods. I wish server administrators would just run vanilla versions of the maps/campaigns and let us players customize the game with client side mods (if we want it customized at all).
Right now when selecting Best Available Servers, I have to join to see if I am weightless, with unlimited ammo, and a Tank in shorts shooting lightening.