What did it for me was 1/2 way through the demo, he went radio room with a teammate behind him with dak dak, as he runs into radio room he starts shooting to his left, There is a t running towards hut but I could not see him on my screen at all, then he runs in and looks straight up to the guy peaking through the vent to shoot him?
Also looks to me like he has some sort of anti-recoil going on, His spam stays very square and doesn't open out much like normal spam would.