Not a lot of helpful info there, and I wonder what "intervened" means in this case. Could mean sticking an arm out to block the path, could mean dragging iron. Also doesn't say whether he was shot inside or outside the store.
If two guys came into an enclosed space like there and I was there, I'd be tempted to draw down on them and have it out. But only if I had the element of surprise, and not if my wife was with me. Just too much that can go wrong. If they were already shooting, of course, then you do what you have to.
Glad the other guy tagged one at least.
The other suspect managed to escape the mall, firing at bystanders as he went. Police said later Sunday that the second suspect was arrested.
I hope this guy burns in hell.