Hi. On my phone
He actually does return to the exact spot. (I can make a video tomorrow showing you) if you watch my yen3 video at 0.25x speed and go frame by frame, use the ticks as a guide:
The second frame of tick 55953 is the exact moment the flick starts (goes from down and right to up and right)
The flick happens
The moment the medigun appears (first frame of tick 55961) (his crosshair is at the nose of it) is where the flick ends
You can actually see a continuation of his down and rightward movement in the following frames (when the critical hit text appears) this is where I believe you think he ends his flick lower
Clip 1. Play at 0.25x speed. (Watch where his charge empties and the bolt disappears for the moment he shoots). The flick starts at the scouts gun, goes up towards his head. He shoots at the top right corner of the leftmost barrel, goes left for 2 frames, and then swipes right
Clip 2. Does return to where the shot started, but it's very clearly a triangle motion (up, left, then down) not a straight line
Clip 3. The flick leading to the right is a much shallower angle, and the flick after the shot is much steeper down. Also of note is that there is a distinct change in speed while his crosshair is closest to the head and as it continues down. This is a human motion of him slowing down
(Also what mild said, plus the literal frame perfect demo shots, imagine if those were a scout clips of someone flicking, coming to a perfect dead stop and shooting on the first frame)