All I can see is that he is wall-glitching with laser-sniper thing that I and others players do sometimes
Yes, but you can see that in the first video at 0:10 seconds and 0:22 seconds, he kills someone with the sniper. On the second video at 0:16 seconds, he gets 2 other kills. So he can clearly see through the wall. He's aiming at very specific places there, that's no luck shot, he knows exactly where the players are.
Can someone post a video showing this is possible? I need to see that the player doing this can clearly see through the wall, because that's the only thing that explains what I wrote above.