From your examples, this isn't a wallhack. The guy is seeing you through the glass. And since you're crouching, it has npc's focus on you. So when you crouch away, he is still looking at you and thus spotting you through the glass. Cuz when you just stand and walk, he is looking down and into the seats/mirror area. His focus isn't in your direction. And That's why the girl doesn't see you. If she did, THAT would be a wallhack. He is seeing you through the glass cuz he is distracted and focused on you from crouching.
What you should test out is do this again, and focus on the guy that is spotting you. When you crouch to the girl, keep your camera on HIM just before you pinch Sato. And see if he's actually focused on you or not. Because from what I see in your vid, when you stand, he isn't focused on you and that's why you're not getting spotted.