The type of holster you choose, would be at least somewhat influenced by your perceived ability to thwart an attempted gun grab.
Uniformed LEO's use Level II & III retention holsters for the very fact that they are carrying an openly displayed firearm. If I were to OC (which I don't), I would likely use a retention holster. I am also trained in the Lindell method of weapon retention and disarming.
I'm not opposed to open carry in the least. I'm actually all for it. It's just not my forte'.
My only warning is for those who do open carry, but either don't use a retention holster and/or have no training in weapon retention may end up on the short end of the stick in a struggle. But then again, that's their decision, is it not? It certainly is no one else's fault if they are not forward thinking enough to foresee a situation where they could lose their weapon in a struggle.
There's no way of predicting how your encounter is going to play out. There's no way to know in advance if you will end up in a struggle over your weapon.
But as far as open carry goes, yeah, I'm all for it.
I use a SERPA, I like it. Some don't. You hear all kinds of junk talked about them, but I have had no problems. You do need to practice drawing from it though. I have missed the button before, and while that yank on your pants isn't a problem practicing it would be one if you need the firearm. One thing I really like is it really trained me to draw with the finger resting on the frame. If you need to shoot, it will find it's way to the trigger quick enough. But having it go to the frame first helps you to not shoot yourself. As far as disarming, if someone is practiced at disarming that holster it's surprisingly fast to defeat it. I had a NCHP officer disarm at an accident. He had no problems getting past the button. Of course, that was without a struggle.
When I OC I tend to keep my elbow locked pretty tight to the gun. And I pay more attention to folks around me.
I see you are in VA. I believe some of the VA folks get together occasionally for OC meet and greets. Maybe check around and see if one is in your area. You could probably find out over at OCDO. Check the VA page.
I use a Uncle Mike's Pro-3 triple retention duty holster when I OC and I have weapon retention training.
As has been stated and implied by others, the holster you choose is merely another tool. You still have to have increased SA and be more conscious of those around you since they can see that you have a holstered weapon.
Should you OC and someone decides they want the shiny thing on your belt you better have the knowledge, skill and intestinal fortitude to defend it hand to hand, up close and personal or as Bark'n said you may end up on the short end of the stick.
Remember guys and gals wherever you travel, every store you go into, every restaurant you eat in there is always a gun present.....yours. It is your responsibility to yourself and everyone around you to make sure you know how to use it and defend it.
The original incident posted here might be a good thing. Does it make me want to OC, no. One thing very few point out is that if you do choose to OC, someone may lie and say you threatened them with your gun. Now it is your word against theirs and good luck with that.
Which is why you always carry your digital audio and/or video recorder and always have it recording when you are out and about. It should be part of your standard carry gear along with the holster and spare mag. There's no reason for "he-said-she-said" in this day and age. Have the recording speak for you.
along with your shoephone will most definately protect you more than common sense, good SA, sound tactics and good equipment.
So in the event of a self defense situation do you draw first or turn on the recording devices?
Harryball never a man purse how dare you. A tactical audio, video concealment rig or a news crew whichever you prefer.