Thanks for the reminder, Peg... definitely an important topic. AS noted above, it is 95% an open carry issue. Of course, if you let people know you have a gun, you have put yourself in an "open carry" situation for practical purposes. Recently, I discussed this on Armed American Radio as a potentially huge issue in defensive training with the currently popularity of Open Carry and the possibility after the Supreme Court rules on MacDonald and we see certain jurisdictions encouraging more open carry.
I also mentioned it on a recent episode of SWAT TV, where I pointed out that a retention holster like the SERPA, which allows a level of extra "retention" automatically after re-holstering can be an advantage for the CCW holder that needs to show his gun and then re-holster. At this point, retention can be much more of an issue than just before the gun was ever drawn/displayed/shot.
I'll also offer that, especially for LE, I have always said that weapon retention is a TRAINING issue, not a gear issue. No holster is going to protect your gun if you have zero awareness and no physical ability to defend yourself in close quarters.
-Rob