So he wasn't an immediate threat to your life. You recognized that you didn't have to end him there.
What was happening with your trigger should've been unconnected at that point.
Perceive. See movement, see a person in your sector, sense a presence.
Recognize. Look at the hands. Does he have something to kill you with or not?
Acquire. First shot from the depressed muzzle. 0.7 secs. It's called a CTE. Critical Task Eval. It's a standard because it provides a planning factor to design scheme of maneuver. In this case, enter and clear a room.
The three general positions with the rifle are low ready, high ready, and depressed muzzle. The standard for a first round from depressed muzzle on a modified kill zone (about a playing card) at 7 meters is .7 secs. That is with your rifle on safe and finger off the trigger. There's no need to point your gun at something or someone, switch the selector lever to fire, and start taking up slack while you're still trying to determine if someone or something is a threat.You can clear a sector faster with your eyes than you can "garden hosing" with your rifle. If you watch professionals do CQB you won't see them waving their guns around, miming their primary and secondary sectors.
If you enter a room and confront an armed combatant, a threat, one of two things is going to happen at that distance. One of you has the drop on the other. Whoever has already initiated the cognitive process to engage is probably going to win, barring shitty marksmanship. Which is why you maintain initiative and violence of action with flashbangs and follow them into a room. I've done a ton of force on force CQB. Meaning against skilled shooters. I have learned over the years that if a skilled shooter has already initiated an engagement on you, your going to take a round. Generally 1 of 4 people in a cell take rounds in a single room of force on force. Against skilled shooters. You're not going to short cut that by almost pulling the trigger on everything you immediately see. It's why we conduct 4 man CQB with overlapping and interlocking sectors of fire. The only area in a room you have to clear by yourself is your critical coner as a #1 or 2 man. Hence why it's essential to dig your corner as you break the threshold.
