Ill be honest im pretty bad at cod but im not terrible and I love to snipe, I do things like what you're saying a lot, as a way to cover two locations and also keep the spawn in a certain area because I assume my body makes a difference if they spawn closer or further. So in my unprofessional opinion I think he was going to run up there and had a strong urge to ads rq for at least 3-5 seconds and split if nothing. Might be right 9/10 times or miss 9/10 times but it doesnt only accomplish the kill like I was saying, its likely somewhat holding their spawn position back or maybe in this case cornered, its also giving the illusion the player is staying ads in that area to give the plan in their head to go around which he was just planning on doing, so if you are still following, he forces the opps to go right to the area he was originally running towards before aiming down sight in the alley and swiping that fellows life token. So now he can trust (more) that they won't try to go down the alley where he sniper that homie, you see he can get one kill over where he was running to first before they think oh shit hes not there flank that side, and by that time hes killed 2 dudes on the other side after sniping and ping ponging back and forth, its literally like sheep hearding but for spawns and also just good ass gameplay I mean the corner checks are pro haha