I don't think the demo is conclusive enough for a ban. I only watched the ticks provided by brett, not all of the demos.
Demo 1:
32k - nothing at all.
42k - fishiest spot of the first demo I saw. It seems like more then a coincidence that his cross hairs line up perfectly when he comes up from the pit. May be luck I dunno. The reason why he's not checking everyone else is because his teammate is out there. He knows that his teammate will be getting shot if someone is hiding in the corner to his right. Plus, rambo hides in that pit a shit ton on that map.
62k - I seen his foot clear as day. He just sprays the door. Aims more at the corner because thats where most people would go.
77k - Same as 42k really, and he is now used to rambo hiding in the pit. He knows to look there.
Demo 2:
7k - This one actually hurts your case. He acts surprised when he see camping the corner. Watch his crosshair jerk, thats a surprise jerk.
23k -25k - He is because his teammate is going first. He isn't looking because he is assuming his teammate will get shot first. I do that shit all the time. He isn't too worried about camping because the fucker is playing human on a dark foggy map. He knows he is pretty much invisible unless someone walks right up on him, and in that case he is going to hear it. Radar explains the tunnel thing easily.
44k - Looks fishy and luck, not conclusive though.
Based on the ticks and demos I'd say unban. Based on the previous vac bans and KAC shit, I'd say permaban. I think a clan member needs to weigh in on the previous shit with his ip, but for the demos provided I am saying legit.