I know that legally it has to be proved that the chl holder intentionally failed to conceal BUT, even if it's an accidental flash, it's all about WHO saw it.
Say you're in a grocery store and you reach up on a high shelf to get a bag of chips. Your weapon is momentarily exposed and a young child sees it. The child then tells his mom that "that man" has "a gun".
The next thing you know you're being approached by a uniform. I don't want or need that kind of hassle in my day.