I think what was meant was that the best course of action may be to run away first. Shooting after moving may be the next best option. If problems arise everyone starts moving first. If they are smart.
You should be moving too. Nothing like making yourself easy to hit.
Realistically, defending against a mall shooter is unlikely. Most likely usage is to dissuade assault or robbery attempts. We can all dream up scenarios where great accuracy is required but shouldn't you then be carrying a 1911 instead of a pocket pistol with a spongy trigger?