...an ex Austin PD Sargeant claimed the CHL holder was legally justified in pursuit as he had witnessed them commit a felony and had the right to attempt apprehension to perfom a citizen's arrest.
It is most probably true that the CHL holder, having witnessed the perps in the commission of an attempted armed robbery, would have been legally justified in pursuing the armed robbers
for the purpose of properly effecting a citizen's arrest. Most people believe that such an action would have been exceptionally imprudent, however, considering that the citizen would be personally liable for his defense and for civil judgements that could bankrupt almost anyone.
However, that's not what the CHL holder apparently did. He pursued the escaping perps and fired upon them as they drove away.
Had a sworn officer done that, he or she would now be on administrative leave awaiting a hearing, most probably awaiting dismissal, and perhaps even awaiting criminal charges (more likely if the perps had been shot).
However, he or she would have been indemnified by the county. The civilian is not.
Everyone involved (along with everyone who was "down range", and along with all of their family members) is
extremely fortunate that none of the bullets fired by the "noble though misguided" shooter happened to hit anyone.
The CHL holder put a lot of people at risk, including himself. At the very least, he could have lost his CHL, and that may still happen; he stood to lose everything he owned; and he could have lost his clean record and perhaps his personal freedom.
For the rest of us, he has provided a clear example of what
not to do.