Life threatening situation in which you decide to draw your concealed handgun unfortunately doesn’t happen in the sterile environment where there is nobody else just the two of you. So if you have the intention of shooting at a clear danger to you or your family, you have to take into account also those around. And the most especially, you need to consider the fact that they have no idea what your plan is or even whether you are the good one or the bad one. Strangers standing around will only see the gun in your hands and in their mind, you are also the threat.
So don’t forget to communicate - verbally or non-verbally. Hand gestures can be very helpful but also short, clear commands as “Out of the way” or “Run” will do. Keep in mind that in their eyes, they see no difference between you and the guy who wants to hurt your or even them. Moreover, if they only heard the firing and then suddenly see you with a gun in the hand, start communicating. If you add “please” or “thank you” after your short orders, it might take shorter time until those strangers realize that you are not interested in hurting them and you appreciate their support.
However, don’t play the hero. The purpose of concealed carry is to protect your and your family’s life. If you are able to help others safely and without harm to yourself or bystanders – that's really great and ethical thing to do, but it is not a requirement.