Good witness, local LE, long range shooting with handguns....
Many of the forum members praise the gun owner for his extended range shot & I, too give him credit for his efforts but I also say that this use of force event should be viewed with caution for other CC license holders/private citizens too.
As an armed citizen, you & your actions will reviewed in detail by law enforcement and/or local prosecutors. Shooting at a violent criminal(s) at long ranges may be a issue to some criminal investigators/District Attys.
I can tell you both as a armed professional & a concealed carry license holder, there are many sworn LE officers would rather have private citizens be; "a good witness" then engage violent subjects.
After the big "Treyvon Martin/George Zimmerman" incident, my local PD(a agency with approx 800 sworn officers) posted a website notice about how citizens should: "not provoke & not pursue" violent criminals.
The concept of shooting at or using lethal force at extended distances will be critized. Even if a sworn LE officer was involved.
Now, I'm not saying you shouldn't assist LE or use lethal force in a critical incident, just use good judgement & common sense.
If you fire a long range shot & it misses or worse, hits a bystander; you'll be in a serious jam. Sworn LE officers have lawyers, insurance polices, union-trade groups and/or public safety officials to support them. An armed citizen may not.
ps; for those forum members who say LE officers have a harder time or are under more constraints than armed citizens, I disagree. A local police sniper on a SWAT call-out shot & killed a unarmed female hostage by mistake. The large PD cleared the SWAT officer of all criminal charges, allowed him to stay on the job and stationed him at the airport.