Ok, I'll explain my train of thought while playing, though I thought the demo spoke for itself.
After watching the demo , the start was abit wierd where he kinda traced true smoke the two guys but later on in the demo i cant see any scanning at the wall that is really supicious maybe some pre aiming at long but thats common since any ordinary player should know that every round someone is rushing there .
B - I took a random shot when I went there, threw a few grenades coz they've been camping there all game. As soon as I heard my teammate shoot his AK i tried to shoot the guy that was on him but he was already dead. Then he got shot by a guy with an awp, which I clearly saw. Since I didn't have a gun I tried to pick up one from the ground while aiming in the sniper's direction but I got shot from my right. Theoretically, if I was using a wallhack I would probably know he was there and instead of having tunnel vision on the sniper I would've probably hid from his sight while aiming to my right.
Long - Of course I'm gonna preaim when I go out of our little tunnel, like where else am I supposed to aim? I saw a flash coming and it was on the floor, which suggested to me that the guy was close to me and just aimed at the floor so the grenade stops. So I estimated when he would come out and I got lucky with a headshot somehow while moving and spraying.
Some hacks have auto screenshot cleaner, which means the cheat (wh) won't show in the screenshot.
I previously had no idea AMXBans took screenshots when you were banned. In my previous ban, there were two people sticking out of the door in de_dust2 and I could only see part of them. Though I have no other proof, this seems to be the most logical argument I have to counter what is being said about the auto screenshot cleaner.