ok it looks like two things in my opinion, First of all he is hacking and he's using a program to help him adjust for the recoil of the guns and two it looks like he's using a shitty mouse.

at tick : 36500 you can clearly see his gun drop and then adjust for the recoil of the pump shotty and the autoshotty.
also if you look closely (and i mean really slow it down you can see his gun do an adjustment for the recoil of all the guns he fires) at any of his other guns it's not aimbot, but in fact a a program assisting him with recoil.

Moral of the story is HAXXXX = Perma-ban