Aside from suspicious activity I consider player technique and ping before taking action. I'm unsure of his ping, and these demos only show short clips.

However, if I had to make a decision based off just this I wouldn't ban. Almost all of his kills were at choke points on that map, he got caught off guard more than once, and from what I saw his cursor wasn't following through walls at all; some times he would even have to turn the other way to correct from looking past the opposite way of which the enemy was running.