Looks to me like he's just a good player. Use this opportunity and learn from him: spacial awareness (based on visual and auditory information), good crosshair placement at all times, recoil control, accuracy, ... is what makes a good player.

Go watch videos of actual cheaters who use aimbot & wallhack so in the future you will be able to better discern a skilled player from a cheater.

No mate, you were cheating. You one-shot me full hp and it wasn't even a headshot (= magic bullet).

For the moderators, further evidence can be seen here: