If he has OPK and is underground, you're fucked. The only one you can kill him on (if you get the chance) is Two Towers and Junk Flea. I agree, OPK should NOT have been public. That's about the only thing pissing me off when I play legit.
cant kill him.....he's underground and I can super jump but he can sit there in the sky. Opk I have seen it's very quick on killing the whole team.....I even load an opk but when i did, no one was vac to the spot. Im sure its a VIP hack from somewhere. It just sucks because you can be kicking ass and then someone does the opk. Its just happening way too much now. I'll try the hack that lets you shoot people who are under you.