It's not that he's good. It's that his opponents were bad. Seriously, in the beginning of the second round, only ONE person on the opposing team went in the direction of B, allowing him to cap it and boost his scorestreak. It doesn't surprise me at all that the weapons he used initially were SMGs (the MSMC with a suppressor is one of the best combinations in the game).
That first minute of the match probably would have been a different story had he been using an assault rifle or LMG minus a suppressor and without the assistance of a UAV or VSAT. Granted, his KDR still would have been pretty high because of the awful competition. I've seen those types of players. They've got smart positioning but really, the real reason they're playing so well is because their competition is not good. I've been thrown into games that were in-progress and the guys on the opposing team had scores of 11-0 and as soon as I see them, I take them out easily because all they're doing is using the best setups (the SMGs) against players who are running around with assault rifles and LMGs or cannot aim with SMGs themselves.