His bad connection gives him good lag compensation putting him ahead a lot of games. People that are ahead are often accused of radar because it literally looks like they come around the corner shooting your exact location every time. Play vs. someone like that, both of you record, then compare videos. What I said will be 100% obvious when you compare how firefights look from each point of view.
tl;dr - He doesn't hack. --- iS*Funke, -Apollo- http://www.youtube.com/user/genoob007