With the scenario we just laid out, you are actively shooting. The problem is that we are reactive shooters. We don't go around shooting at people just because we thought they were armed. We have to wait for some type of danger cue and react to it. Hence, we are reactive shooters.
The other problem is that we are not given a sufficient amount of training time to practice a flashlight technique. Years ago the "experts" said it would take 4,000 to 6,000 repetitions to make a tactic intuitive to the officer. Years later, the estimate rose to 6,000 to 8,000, and now some say 8,000 to 10,000 repetitions are required to make a tactic "instinctive" to the officer. In reality, no amount of training time is going to override your instinct to survive. It's just that simple.
If a tactic is too slow, too complicated, or too confusing, then the tactic will not be used under stress. Your brain will automatically override it for one that is easier, quicker, and simpler to perform. Or, the flashlight will not be used at all. In some cases, you may purposefully not want to use your flashlight.
The problem is that sometimes mistakes are made. There have been studies conducted by police organizations in which the officer couldn't tell the difference between a wallet, a cell phone, and a handgun in low light. So some type of additional light source, like your flashlight, is beneficial.
Let me give you a flashlight technique that will work every time, under any condition. Turn the damn light on and point it at whatever you're trying to shoot. Why do we need to complicate things with all these different techniques? I'll say it again. Turn the damn light on and point it at what you're trying to shoot. You don't have to be exact, just as long as you can see the bad guy and what he's doing. If that means that only a portion of the halo around the center beam of the light shines on the bad guy, then so be it. Just as long as you can see the bad guy well enough to acquire and identify the target. In other words, yes he is a bad guy, I can see him, and he does pose a threat.