Hai.
1. I see no wallhack at all. He was just trying his luck by shooting there. I usually shoot everywhere in that place when im CT and got an awp.
2. As you can see in the whole demo he was playing normally.
3. Bring me back my 20 mins of my life !
4.The one where the T dies and his model falls throught he wall while hes looking at him
And as far as i remember (sorry i forgot
) bullets traces were falling from there , maybe he aimed at it 
Bai.
I am sorry to brake it to you, but did you watch the demo?

How is your skill? Do you play like him? So lets assume he was only spamming the wall where the T might of been, ok? So there are moments in both demos that the T shows himself slightly, either with a gun or just small portion of the body, what does he do? He doesn't even shoot the wall or doesn't try.
I don't think it's smart wh at all. I think he had the basic wallhack on and was playing like he doesn't have, which is extremely hard since you don't act the same when you know where the enemy is naturally.
I see 2 things, a lot of wall scanning and as Drn said, his croshair a lot of times rests on the enemy, we can of course add it to coincidence, but then the second thing is that his skill is so low, you can see it on second demo pistol round or even with snipers which seems his favorite gun. His skill is very low and I raised my eyebrow when he added rainb tag on second demo.
Don't get me wrong, I was rather skeptic about the demo, but the more I saw, the more it seems wrong in so many ways.
I have my experience and of course if you know where to shoot good for you, but when the enemy is slightly visible and you don't try to get a hs through a wall with a sniper is somewhat wrong.
Opinion =
wallhack.