How can a person forget something they hadn't noticed five seconds before something they did notice?
How can she have not noticed the first shot? She said she did notice it. She counted three shots. The first horrible ear-shattering noise followed by two more shots. Are you suggesting that there was a shot at z124 that she did not notice but counted three shots after? That's four shots.
You seem to be making up excuses for witnesses missing this shot that you made up at z124.