I definitely wouldn`t call this sick. You had 6 (!) secs to aim. And like craven said, he didn`t notice you on his radar, which means he must be pretty noob. 1 out of 5.
Why does this have a 4.5 score? I had a clip the other day that was 20X sicker, and 20X more clutch, but I never even thought about uploading it to the gameroom. That kid didn`t even glance at his radar for christs sake.