First of all I believe quality training is a positive thing.
Also, one needs to be aware of the mental aspects and split-second decision making skills associated with being involved in a situation like Ft. Hood or a mall shooting.
*For example, are you by yourself in a public place when a shooter goes on a rampage or do you have family members to protect?
*Finding cover and concealment, whether alone or with family, and for what (if any) reasons do you break concealment?
*I do not advocate charging in like ol' John Wayne, but if the assailant is heading your way with guns blazing, do you wait and see, or strike to try and end the attack?
*If LEO's are on the scene and engaged, but the fight overlaps into your safe zone of concealment, do you engage and risk being mistaken by LEO's as a hostile target?
As with any situation, there are many variables to be considered.