Reasonably considered, your odds of being struck by lightning are better than your odds of being confronted by a group of terrorists. Does this mean there is zero risk of such a thing? Of course not.
So what is a reasonable response? Obsessing on the least likely threat is no help. Making yourself the best you can be at the skillset you need to responsibly go armed IS reasonable. IMHO that translates to training and practice. Quoting from the article linked in the OP:
The problem, then, lies in the hands — more specifically, in the training — of the officers so armed. If a police officer does not have the marksmanship to kill (or even hit) a suspect at 20 or 30 meters with aimed fire from a battle rifle, there is little chance he can control the automatic fire from an assault rifle or submachine gun effectively. In the end, the attackers outclassed the Indian police with their marksmanship far more than they outclassed them with their armaments.
In the United States, local police would be aided during such a confrontation by the widespread adoption of “active shooter” training programs.
Today, many police departments not only have a policy of confronting active shooters, they also have provided their officers with training courses teaching them how to do so. Such training could make a world of difference in a Mumbai-type attack, where there may not be sufficient time or resources for a specialized tactical team to respond.
Police and security agencies commonly examine serious terrorist attacks for tactical details that can then be used to plan and conduct training exercises designed to counteract the tactics employed.
Yet a certain percentage of private citizens who carry a firearm can be counted on to insist that 'they don't need no steenkin training.' The words of author and historian Barrett Tillman come to mind...
lpl ("You won't rise to the occasion--you'll default to your level of training.")
