Are you saying there are hundreds of thousands of situations where a CCWer shoots someone because they moved their hand toward their waist? I doubt that.
There are hundreds or thousands of similar situations every year that normal people get caught up in. What percentage of those people are prosecuted?
The statutes covering justifiable shootings as they relate to police and non-police are usually pretty similar. Would a reasonable person have been in fear for their lives or the lives of others in a given scenario? If yes, the shoot is typically considered justified. If no, it is typically not. Sure, sometimes there are other factors which can play a role and the usual "but, but, but, TEJAS!", but that is the basic standard.
The major difference is that police are required as part of their job to interpose themselves into situations where most of us would not be expected to do so. Thus, saying "well, if a CCWer were hunkered down with a firearm trained on a doorway commanding the occupant to come out in response to a 911 call ..." is sort of hard to address in a reasonable fashion since the scenario is so far fetched.
However, there are plenty of similar enough cases where, for instance, a homeowner wakes to find someone skulking about their darkened home, kills the "intruder" whom they thought were making a bad move only to find the deceased were unarmed and actually a drunk neighbor or a family member or something. Yes, an innocent person is dead, but in the shooter's shoes another reasonable person would likely have done the same thing, so they are not convicted.