I suspect you're over-thinking things a bit. Not uncommon. We've all indulged in it at one time or another.
You were probably using a specific aiming point when you were target shooting, right? Meaning you were "following the hole" after the first shot in each target area? Hang up an old T-shirt on your target and see how things may change when the "hole" isn't nicely punched and clearly visible through paper.
Also, you were probably standing comfortably, shooting at whatever rate-of-fire is comfortable for you, right? 1 or 2 handed? Even, or least consistent, weight distribution?
Shooting situations tend to happen unexpectedly, and are usually referred to as dynamic, chaotic, rapidly evolving events that more often than not involve reduced light conditions. Elevated heart rate from the hormonal fear response (meaning not just from some simple physical exertion) can start to adversely affect things, too.
I remember one study by a major state agency which found that over the course of many years, reportedly upwards of almost 65% of both the officers and their attackers had been in motion throughout the shooting incidents.