Since I don't like fresh, I'm not just going to say he's hacking.. I actually watched it about three times, One with r_drawothermodels 2 & voice enabled 0, then with r_drawothermodels 2, and finally without anything.
*A few times may not be exact, but they're probably a few seconds away.*
1:00 - Looking at the wall to see if anyone is coming, can hear sound but mics mildly drown that out.
1:38 - Looking through the boxes and aiming at the enemy with a sniper, who is aiming at him.. ..can hear footsteps, but is aiming directly at the enemy's chest. Could hear XxDkillaxX's footsteps.
2:12 - Looks at the enemy often, sound drowned out by Lazy's mic
About 3:00 - Looking through the crate (Looking directly at it) to see where the enemys are
About 3:40 - Looking through the wall (not crates) he is camping next to, no one would be dumb enough to look at a wall where you cannot see anyone (You'd move your mouse quickly past it just incase someone is walking towards you) Since he said he was in Cal Main, he shouldn't be staring at walls. But afterwards, you can hear the enemy walking towards him.
4:10 He looks through the walls again just like 3:40, but the kill at 4:26 you can hear the enemy spray their spray
Since I used to wall hack years ago when I was a kid, I can usually spot wall hackers.
But if I got anything wrong, just correct me.