On the average you would have to shoot 83 three-shot groups to get one which was less than or equal to 1 MOA (about 30 inches). Only about 30% of the shots will hit a 18″ x 24″ target
You really have to look at the images to understand what’s involved. This isn’t about skill, it’s about the capabilities of the ammo and the rifle. It was a lucky shot, which no one doubts, yet still within the capabilities of the equipment.