Although I certainly support CCW and right to protect, I wonder if this guy maybe over-stepped the original reason for CCW.
I suppose if the shotgun totin' perp pointed or threatened the CCW holder, certainly he/she would be justified in self-defense use of his firearm.
However, if he/she was just "playing cops and robbers" and was NOT a member of LE, there MAY be some disagreements on his/her use of a defensive firearm legally carried.
>>> I wonder if this guy maybe over-stepped the original reason for CCW.
I hear what you are saying but the answer is no. The civilian did well. The crime was under way and the shotgun showed that mortal danger was real and immediate, not speculative.
Waiting for an innocent party to be killed before responding was the choice you suggest. Rough on the victims.
Hazard of the trade.