I was walking through one of my favorite sporting goods stores and wandered into the holster isle. My goal was to get a Level II holster that used a latch instead of a strap over the firearm. I found a fairly inexpensive Blackhawk Serpa holster, marked for clearance. I bought it.
It is an OWB holster, not my desired configuration. It did have a latch that must be activated to remove the pistol from the holster. For all intents and purposes, I had achieved my goal. I did carry with it a few times but prefer an IWB carry solution.
I showed the holster in a couple of my classes. Then, I saw a very strong warning from an instructor to not bring that holster to his classes. I did some research and found he is well founded in refusing that holster on his range.
The problem is the retention latch release is positioned directly above the trigger guard. When drawing the firearm, the finger is positioned to rapidly engage the trigger rather than indexed. That means it is extremely easy to have an inadvertent discharge while drawing.
This holster was issued by the U.S. Army. It has been replaced due to the safety issues. Active Response Training posted an article (https://www.activeresponsetraining.net/the-serpa-compendium) that gives some rather graphic evidence against the Serpa.
The basic problem is the involuntary hand clenching of the fingers when trying to draw quickly. This involuntary clinch is the root of the “Keep your finger off the trigger until ready to fire.” safety rule. The placement of the release puts the user’s finger directly over the trigger well while drawing the firearm.
With enough training this risk can be greatly reduced. However, the risk will still be a danger, especially at the start of the training. After extensive training the risk will still be there. Very few training programs will stress you as much as a lethal threat that must be engaged quickly.
I use the holster to emphasize having extra retention protection when open carrying. I don’t recommend open carrying in my classes but address it because my students may elect that configuration. When your firearm is exposed, having a level II or III holster adds a margin of safety when a threat may try to take the firearm.
Having a release lever to engage brings some extra considerations. While the Blackhawk Serpa is the holster I have been talking about, it is not the only one that has this configuration. It is my strong recommendation that you avoid any holster that has the release over the trigger well. The Serpa does have some knockoffs. Other holsters have the release button along the frame or on the back. These are much safer to use.
Having a retention release mechanism brings another aspect to your carry considerations. The release is a mechanical device. As we all know mechanical devises can and do fail. A retention release can be jammed by foreign objects. These objects may be introduced if, in your response to a threat, end up on the ground. Debris kicked up can work its way into the holster.
So, to answer the question of training aid or consumer warning, I say both. I will still use the Serpa, but only in class. I will not carry a loaded firearm in it. I will show that this design has some serious shortfalls.
What equipment you carry is your decision. My aim here is not to bash the Serpa, only to point out safety considerations with that configuration. If you choose to use a holster in this configuration you should be aware of the safety considerations.
Is a retention device necessary? Again, that is up to you. If you open carry I strongly suggest you have a Level II or III holster, specifically one without a release over the trigger guard.