lmao have you ever swiped your mouse before? it's normal to move a little on the opposite direction since you're resetting your mouse from the left back to the center and sometimes you put it on the mousepad too fast.
Are you an idiot? Its not about his flick or his swipe. Run it at 0.25 speed, while he turns his mouse almost 180 to the left, his mouse pushes back to the right, it actually aimlocks back at the player behind the wall.
What the fuck do you think I was talking about idiot? He swiped once and had to lift the mouse all the way back so he could swipe AGAIN and that made him look to the right where he coincidentally "looked" at the guy through the wall.