A 93 year old woman or a 10 year old boy firing a gun is exactly the same threat as a 20 year old, 300 pound guy firing a gun.
I have no idea whether this particular shooting was righteous, but the age and sex of the shooter is irrelevant.
This is, BTW, one of the drawbacks of widely available firearms. With no gun involved, the age and sex of the person becomes very relevant and the situation could almost certainly have been defused without anybody being injured or killed.
I see I posted the above to the wrong thread. My apologies.