Its a bug in Medal of Honor that I believe stems from the mike torso or mike legs file if I remember correctly.
Basically the bug occurs when you press the USE key and jump off of a ladder at the same time. The player then enters an odd looking state referred to as "sharking" as shown in the video link below. The player who is now "sharking" is not killable by other players shots.
Hey Shadow !
Thank you for your explain me that sharking / glitching.
I play on Battlefield 1942 too and there are the same and other Glitch bugs in every map.
My favorite is on El Alamain where i can go into a Bunker with my Tank or on Stalingrad i can go behind the Fence when i using a Car etc.
Some Time its nice to have but some player are using this glitches too often. But there some Admins on too, so they will be kicked or sometimes banned for this.